If you discover that YOU want to stay in a relationship with her then quit drinking, get your act together, and be nice to her. If she likes how you've gotten your life on track and still wants to be in a relationship with you then at least you set up everything nicely. If not, then just keep together and look for a new girl.

If you don't want to be in a relationship with her then keep doing whatever you want to do, but taming your drinking habits would still be a healthy decision. Unless you meet a woman who likes to get as drunk as you as much as you do then you'll probably be alone for a long time.

Her actions on Facebook could mean anything. Shrug it off and don't let it get to you. Stop reading her signals they will confuse you. Just do what you think you should do for what you want in life.

You do sound somewhat bitter but who isn't after such a long relationship? Four years of your life is a significantly long time, and maybe you feel like failure but that is life and these are the lessons we learn. If you don't learn anything from this then you'll be doomed to repeat it with your next relationship and any after that.

If the property you two share is under your name you should find an appropriate time to discuss with the arrangements of her moving out. Be cordial but don't be a pushover. Be polite but I wouldn't give her any money. Do what you can to help her that doesn't strain your coffers or is beyond your expense.