Well first off, if you don't get over the lack of self confidence you're going to have trouble getting a girl to go out with you. Why don't you start focusing on your positive attributes instead of your negative ones? Self-deprecating people are just no fun to be around. I've met some less than attractive guys who made up for it by being funny and smart and CONFIDENT.
Work on that, and when you've managed to convince yourself that are are worth someone's affection, then go ask for her number.
Live as if you were to die tomorrow. Learn as if you were to live forever. - Mohandas Gandhi