Really really down...

I'm really depressed for so many reasons. I don't really know what to do!!

Anyway, I'm 20 and a student.
The thing that has gotten me down most at the moment is that at the weekend my girlfriend left me for almost no reason, she said that because she had been nulling her feelings for so long that when she fell in love with me, all the other really bad feelings started coming back to her making her really depressed.
After that I self injured for the first time, to try to cope.
Although it has made me feel worse I really can't remember a time when I felt much better, throughout all my late childhood and teenage years I had almost no friends and I spent most of my time alone in my room trying to avoid my parents who would get quite verbally abusive to me if I stayed near them for too long, saying things like "I hate being near you, you're so miserable you're making everyone else miserable, cheer up or go away" and "You have less worth than a pet dog"
It also doesn't help that I also have Aspergers Syndrome as well as a complete lack of empathy, and a general uncaring about other people, it's not like I want to be that way but I just can't care.
I don't know whether it would be worth having therapy because I can't speak about my feelings because alot of the time I really can't recognise what I'm feeling and thoughts and ideas tend to just get stuck in my head and I can't express them to other people which is so frustrating and it makes me feel even more alone.
I also pull my hair out too, (Trichotillomania) which isn't good, but I don't know what I can do about it.

Sorry about the long post.

I sympathize. I can't really give much advice about what to do because I'm in pretty much the same position as you are - cutting, depression after breakup, lack of empathy, autism spectrum disorder, and lifelong lack of happiness and friends - but I can advice you what you shouldn't do: don't depend solely on medicines. They can help, but they usually can't solve the problem alone. I've tried at least 20 medicines now, and none have really helped.