This is how I learned to talk to guys, so it might help you out.

When I was about 23, I started going to these parties... I had a friend that threw a speak-easy at his apartment once a month. What ended up happening is that the exact group of people, a few fading in and out, would go to his house and get drunk together, usually about fifty people a week. This went on for a few years, the same people partying together and bonding. Now, years later, they're still some of my closest friends, and one of them is my husband.

This little parable does have a point, believe it or not. Before I started going to these parties, I was absolutely mortified to initiate a conversation with the opposite sex, and it felt like I was fatally nervous. I became able to speak with them because we all got to know each other very well in a group setting, before getting to know each other one-on-one.

You say you've got friends, and social difficulty in general is not your problem. If you get nervous around girls when you're by yourself, then do what you can to meet up with them in group social settings. It's a lot less intimidating. Also, maybe you're one of those folks who really needs to get to know someone before intimacy is possible, and that's not a bad thing. Take your time, get to know them. Think of them as friends first, and then let the romantic attraction happen later on in the relationship. It'll make you a lot less nervous.