The first thing that pops up in my head is that you are looking for confidence. Well confidence come from KNOWING things and being comfortable in certain situations. I agree with 6nemesis9 in that you have to work in baby steps.
So first congratulate yourself getting out there. That's the first step! Second, start with going out to a place where you feel comfortable. It doesn't matter where it is, library, supermarket, park. Just go there and observer pple and try to picture in your head what you would say to each one of them. Do this for about a week straight without fail. Next, talk to people that are paid to talk to you, like the sales girls. I know you said you get nervous but I'm to tell you that IT'S OK!!!!!!! It's ok to because it' their job to talk to you, so you're not gonna be rejected. So your goal is just to conversate, that's all. Nothing more. No number, no kino, just talk. Do this for about a month and you should be used to talking to people and making strides against your approach anxiety.
It's not something that disappears over night. But you can lessen it little by little everyday. Good luck!