I have three big problems here... I've mulled over them by myself but now I pretty much just need to vent, and hopefully some of you can give me some advice from experience.

WARNING: LONG ASS POST.

1) I absolutely hate my girlfriend’s parents. Mainly her dad, who she lives with.

Her parents are split up, and I've met her mom who is okay, still a bit of a bitch, but bearable and actually seems to love her daughter. Her dad though, holy fucking shit... I haven't even met the guy, she won't let me. She says that no guy has ever lived up to his standards and she doesn't want to hear him saying awful things about me. This guy ruins my day consistently because of the state of depression he puts my girlfriend in. I'll make plans to take her out to lunch or something, she'll call to check in with him (he requires her to, she's 19 btw), and more often than not I'll see her eyes start to water up, and then she'll just start grunting in agreement, and once she hangs up its almost always one of two things. "I have to go home" or "I can only stay out for about an hour". This has happened so many damn times when we've made plans to spend the whole day together, which we don’t get to do often because of our school and work schedules.

Example:
Earlier today, I woke up feeling absolutely amazing. Talked to her in the morning, made plans to pick her up from work and grab some lunch before I had to go to class. I get to her work and her ex is just standing outside (next problem). So she's already in a bad mood, I start driving around asking where she wants to eat and she calls her dad to check in to let her know that she’s going to get lunch and will be home right after (even though he won’t be home until like 7). During the check in call she also asks when he'd like to go to the movies tonight for his birthday (it was like a week ago but everyone was busy). He lays into her about how it was her job to pick a movie time and then he said something about how since she made him breakfast in bed on his actual birthday that she's off the hook so he'll just do it himself. That doesn't sound so bad but think of someone yelling that at you in the meanest, nastiest way possible. The whole time she's pretty much just trying to get a word in so she can explain, and he just hangs up on her. Her eyes tear up, she goes silent for a minute or two and I have no clue what to say. Then it’s the "I have to go home now".

This type of shit pretty much happens at least once or twice a week since she's started living with him about a month ago. (third problem) She keeps saying she wants her family to be a part of her life, but then tells me that they all act like they don’t want her as a part of theirs. I don’t know why she wants this guy to be a part of her life… in my opinion this is the one person she needs to get away from.

2) Her ex won't go away.

Her ex doesn't seem to understand that it’s over and that she's done with him. He texts, emails, calls, shows up at her work, etc. I've asked if she wants me to handle it and she keeps saying no because she wants to do it her way (which isn't working). They were together 2 years, so I didn't expect him to just disappear, but this guy is in the way too much and is messing with her head. She doesn’t want to hurt him anymore and wants him to be happy, but she finally realized that she can’t be responsible for his happiness. And now that she’s taken on this attitude and stopped codling the guy, he’s depressed and is constantly showing up to talk or something… I haven’t asked what he shows up to talk about but I’m pretty sure it’s along the lines of “TAKE ME BACK”. And when she puts her foot down and basically says stop contacting me, he gets depressed and starts sending hurtful texts, etc. She finally blocked him/unfriended-whatever’d him on facebook (whoopy) but still won’t block his number. So if her dad isn’t putting her in a depressed state, this guy is either friendly because she’s giving him some attention, which I have a huge issue with because it makes his lows that much worse, and I’ve told her that, or is sending her texts that make her feel like shit because she’s not responding or telling him to stop.

I’m at the point with him where I’m about to deal with it myself the next time I see him, whether she likes it or not. I think she just doesn’t want to end it on bad terms, but things are not getting better with them staying in contact so I don’t see any other way than to just cut off all communication. I told her that’s what she needs to do, and that I’d let her handle it, but she’s not, she’s just dragging things out… so, yea, I feel like I need to step in now. I’m not going to get violent or anything, but I’m not going to hang back in the shadows because she’s afraid him seeing us together (she doesn’t know I’m with her, but he knows she’s seeing someone else) will send him into some uber depression or something. Basically I’m about to stop playing by her rules and start handling things myself because nothing is getting done. Someone is going to end up hurt one way or another, and it should have been over with a long time ago.

3) Living situation.
Her life up until probably about a year ago has been pretty fucked up. Horrible family issues, obviously, horrible situations with friends, just horrible experiences in general. Because of all of this she has problems, mostly emotional type stuff, but she’s made tons of progress through sheer force of will on her part and I’m proud of her for that. I’m not sure who said it or recommended it, but someone told her that keeping a pet would be great for her mental health (this was when she was like 12 I think) and ever since then she’s stuck to that and has said she feels it really does wonders for her.

The problem is that the only place she can keep her cat is at her dad’s house. Her mom doesn’t want to deal with it, plus there are price issues with the landlord to allow it. She’s trying to go to school, so moving out and working 40 hours a week to pay rent doesn’t really work. Plus she already did that once because of issues with her family, and she got screwed over by her roommates, so she’s already afraid of trying that again. She has no car, parents won’t shell out for one. I pretty much drive her everywhere now when I can, buses down here are crap.

Hell if I lived on my own I’d let her stay for free but I still live with my parents. She’s welcome over as much as she wants but she has to take care of her cat, and unfortunately that’s a no go here. Even when she doesn’t need to be there with the cat, she usually has to watch her little brother since that’s part of the deal of living at her dads. I’d be completely cool with that if I was allowed over, but her dad pretty much doesn’t allow anyone over anyways, and since she really doesn’t want me to meet him I’m screwed. I barely get to see her now since she’s pretty much a prisoner in her own home, and when I do get to see her it’s usually cut extremely short and ends with her in tears and me wanting to murder kittens because all I can really do is sit on my hands. It’s a family issue, what the hell can I do, right?

The way I see it, there are 3 options. 1) Keep her cat, keep living at her dads, keep feeling like shit day after day and keep dreading going back home. 2) Give up the cat, live at her moms, enjoy some goddamn freedom. 3) Move out again, work as much as possible, take a year or two off school and go back when things are stable. She’s also told me she had an offer from her best friend who lives out of state to come live with her, and she was really considering it before we met. So now I have this nagging thought in the back of my head that one day I’m going to wake up and she’s going to just be gone because her family pushed her too far and she just up and left.

So now I’m pretty much at the point where I’m starting to think if things are going to work out. Should I cut and run… I don’t want to, I really don’t want to, but if things don’t change I don’t think I’ll be able to deal with all the ups and downs for much longer. This girl is amazing, I love everything about her. Life is great when she finds time to get away from her family and just be herself, but it just seems like everything is crumbling down on her and I can’t do anything to help other than say “If you need help, I will be there.” And I mean it 100%, I’ve done it. The simple solution in my eyes is to ditch the cat, and I wish I could communicate that to her somehow without her flipping out. I’m really afraid to push the issue with her because I strongly feel that’s the best course of action, but I don’t want to be just another person trying to push her into something they want her to do… and with everything else that's going on, if I’m not there for her to lean on I don’t know what she’ll do. I’m just mentally exhausted from it all…

So, what the hell do you guys think of all of this? How much of a little bitch am I being? Are there any compromises or courses of action that I’m not seeing that might help? Am I overreacting? Hell, any insight at all would be helpful. Most of my friends just give me a “That sucks dude…” or “It hurts when you care about someone…”
/sigh

TL;DR
My girlfriends parents are slowly driving her into massive depression, her ex wont leave her alone, her living situation is horrible, her cat is blocking most of her good options in life, and I can't really do anything aside from sit on my hands and hope she lets me help her.