Confidence = You're okay no matter what. Independent yet engaged in the physical and social world around you.
As soon as you stop worrying about being sexy while simultaneously trying to stay connected with others and healthy, you will be sexy. Look after your apppearance, get healthy, and just try to build good relationships with your friends. As far as when you're ready to meet some women, enlist the help of other women and try to hang out with some hot female friends. They will provide social proof.