I like this girl a lot but I get nervous?

There is this girl that i like a lot and think is so beautiful, she's in my friend group and we have hooked up before at parties and I talk to her a good amount on the phone (texting) but I become kind of distant when im around her at times because I get nervous and dont want to make a fool of myself around her but at the same time I would love to just walk up to her and tell her exactly what I think about her . What should I do, I really dont want to let this opportunity slip past me.