Friends are no longer there... Can't find a reason to stay

So, I've had issues with friendships ever since I was a kid. My best friend growing up abused my friendship, and basically only wanted me around when it was convenient for him... which I did not realize until my college years. Middle and High school I spent being made fun of and being called gay. College was better, but towards the end, much of the same... Accusations of homosexuality were much more frequent and more widespread. The girlfriends that I had were ALWAYS (I kid you not) stolen away from me by people I considered to be my best friends.

I finally thought things were getting better my senior year of college. I was introduced to a new group of friends that lived by my hometown, and we all hung out a lot and became a lot closer. After graduating college and realizing the people I was "friends" with there were immature and were not going to change, I looked forward to my new life with my new friends.

I ended up getting an apartment with two of the guys I considered to be my closest friends. It's been several months now though, and both of them seem to be more distant, and one flat out doesn't like me. I started going to see a psychologist a few weeks ago, but it seems to be a huge waste of money. I tell him what is going on in my life, and only seems to tell me what I already know.

Recently, things took a turn for the worst... my one roommate is very pissed at me for something that isn't that big of a deal (IMO), and now he will not talk to me, hang out with me, or even be civil with me. Tonight, when the other roommate came home, they both made plans to go out and went out of their way to not include me. When I asked what they were up to, they ignored me. When I asked to join, the put me off.

Most people wonder why I put up with people who treat me badly, but the truth is I have no one else. I don't have any friends besides this group, and i'm the type of person that relies on a best friend heavily. I'm just starting to realize that I don't have one.

I've always tried to be the best person I can be, and to be caring, but it seems to keep getting me no where. I do nice things for the guys and try to help them out, even financially, and I feel like I get nothing in return. Therapy isn't helping, and I'm starting to get physically sick when they do things like they did tonight.

I really don't know what to do.