I can tell that you are desperate and miserable. But I think this guy has made it clear that he’s just not that into you. It was probably too much responsibility to be your only friend. You are so terribly lonely and needy that he might think he couldn’t possibly give you what you need.
The answer to your problem is not to get this guy back. The answer is to figure out just why it is that a sensitive, passionate person like yourself hasn’t been able to make a good circle of friends. Everyone needs a few people to hang out with, to do things with and to talk to. Being with other people is what gives us all comfort and helps us grow.
Drinking isn’t going to solve that problem. Going after a guy who doesn’t want you as his girlfriend isn’t going to solve it. Crying in your room isn’t going to help you find friends either. You need to get yourself involved with some things that will help you meet people your own age who like to do things you like to do. That may be hard at first. You seem to be way out of practice. But I”m sure there are places in your town where you can volunteer some time or clubs you can join that focus on things you like to do. Often those are good ways to get started being social again.
Please don’t tell me “I’m not a joiner.” You are. Everyone is. It’s natural to want to be with other people.
If you can’t make yourself get involved with people who could be friends, then I think you should get some help from a therapist. There’s no shame in needing some support and some practical advice if you are too shy, too nervous, or just plain don’t know where to start.
Please start doing what you need to do. No one should be this lonesome.
I wish you well.