Don't know what to do anymore

Hey, I'm new to this board and I don't speak perfect english, so if I give any mistakes, I'm sorry

So, I have a depression for about 4 years now, this all started because of a love story which is now 100% over in my head so that's not the problem anymore. The thing is when I was in highschool I had a best friend and we talked everyday on the phone for about 3 hours, she would tell me everything about her and I would do the same. When I started college, we sort of had a fight and since we didn't see each other at school we stopped talking. She basically was my only friend. Last year we met and everything was ok, we had a cafe and talked but she just wasn't the best friend I used to know anymore.

Now, on the 2nd year of college, I have people I know, not friends, 2 of them are from college (and I'm pretty sure one of those people doesn't like me because she keeps on letting me out of conversations and doesn't like when I have a good grade for example). Outsite college I suppose I have 2 people, but they are constantly hurting me and leaving me behind. The only person I have is my sister but because I feel she is the only person that I have I'm sort of annoying her and she treats me badly because of it.

I really don't know what to do anymore. Everyday I'm surprised that I still have strenght to carry on. I have no friends, no one likes me, no guy ever likes me. As much as I hated someone, I would never wish for them to feel this alone.