Hi, I recently got a girlfriend, and we have been having sex for about a month and a half now, and I have only been able to come about half of the time. Sometimes it is because I was just drunk, although I have come while drunk before, but it's really starting to bother me. Last night for example, she came over and we had sex, and I was going for a good 20 minutes and came a little close sometimes but didn't come. I took a little break and put on a new condom (just in case) and started up again, but after like 10 minutes, again nothing so I tried to switch positions and my erection went away and wouldn't come back. Shit like this has been happening a lot, I don't know what to do. I don't really come close to coming when she gives me a blowjob either. Any advice? I'm dying here.

By the way, I'm 20 and have been using those ultra thin condoms, doesn't seem to help much.