FOBU, needing advice!

Ladies, I need encouragement. Please read!
For those of you who haven't heard the term FOBU, it stands for fear of breaking up. 
This is the second time in a year that I've been in a relationship I wasn't happy in, and I am too afraid to end it from fear of being alone. 
I don't have many close friends and I get anxiety when I am alone (by alone I mean physically alone, like sitting by myself in a room, not single alone). Because of my lack of friends, I have no support group and nobody to rely on for comfort which makes me terrified of being isolated and alone outside of a relationship. 
I am currently in a relationship I know I need to be out of. I can do better than this person (he is disrespectful and does drugs which I do not put up with) and I do not want to spend more of my life in this relationship. 
My problem is, I am so afraid to end it because I'm scared to be alone. Any advice, ladies? I have to break up with him. I just need a push. Thanks so much!