Get therapy! Seriously. If you're like many you'll blame yourself and a therapist will help you deal with those feelings and come to really understand that it takes two to make a relationship work and only one to screw it up.
Get some professional help - see a therapist and talk to him/her and after a while you'll start feeling better about what you've been through and start rebuilding your self-confidence.
It's all about how you feel about yourself.
And don't forget that even when you're "ready" to start dating again you're not going to be ready for a while (so don't get serious about the first person you date - it most likely won't work).
Good luck!