First get your life on track, find something that interests you, get educated if need be, get a nice job. Doesn't have to be something impressive, but something you'll grow comfortable with.
Self confidence is not achieved by success, but by positive expectations. People with confidence think: "I'm going to do this." while people without have failure in their heads. It's OK to make mistakes, so don't be afraid of it should not cloud your mind.
A girlfriend can't help you with this, first figure things out for yourself, make some friends if you can, find people with similar interests (the internet is abundant with groups to share hobbies and what not).