Calm down
I felt the same way about a really hot girl a two years ago. It was one girls at the regional Hawaiian Tropic girls search. Couldn't get her out of my head, had trouble sleeping at night. I though I was going going crazy.
Fortunately the girl was a local and I saw her again at The Whiskey Inside of Green Valley Ranch. I though I was going to loose it, but after I had a few shots and a few drinks I was all loosed up and ready for office hours. I worked my way in there, got the didgets and eventually rounded the bases with her over the course over about two or three weeks.
Obviously things didn't work out with her in the long run. After the alcohol wore off from the first time I met her I realized how easy it was to pick her up but being nervous to the point of making myself nuts wouldn't make anything better. So get yourself undercontrol. What you do from that point is up to you but you have to have a clear head in life regardless of what you're doing. Girls or otherwise you need to be some what focused. It makes life a lot easier and a lot less stressful.