I'm Socially Awkward?

I never got out much as a kid, and I think I'm lacking basic social skills. I ALWAYS seem to rub people the wrong way. I'm an attractive girl but my looks don't get me far without a personality. I'm never "myself" because I worry too much about what people will think of me. When I go to parties people like me at first, but the more I talk I seem to push them away. I have a habit of saying dumb things to impress others and it makes me look like a doosh. My friends are also super skinny and gorgeous and they always seem to get more attention/approval from others. ESPECIALLY guys. I want to be that girl, the girl everyone likes, respects and wants to be around. My looks help but I NEED to let my personality shine through and I don't know how. I'm basically too nervous and anxious for approval to just be myself. How do I get over this and stop being so socially awkward???