It's funny, I have major approach anxiety but no kiss anxiety lol
When I get into a set and settle in then I'm ok.
Back to your problem though, you cannot just lunge in for the kiss. I think you are waiting for the right moment to pop up and then lunge at her. There's a few ways to determine if she's ready to kiss you but here's my favorite way
First make sure you have isolated her and you are away from your friends and her friends. When talking, don't say as much and just maintain strong seductive eye contact with her, she will feel the vibe too. Try to hold her hands while holding eye contact, then I like to put my hand on her lower back and pull her into me just a little bit too quick so she is slightly off balance. Shows your masculinity, if done right, she should laugh because she almost fell over.
Now your faces should be pretty close, still maintaining eye contact, look from her left eye to her right eye then down at her lips and repeat. SPend about 2 seconds moving from eye to eye then the mouth. Watch her and see if she is doing the same or that she goes really quiet. If she is doing the same, you can slowly go in for the kiss. Beleive me, if she didn't want to kiss you, you wouldn't have even got to this stage in the first place. I used to worry about my first kiss too but it came out so smoothly, and the girl thought I had kissed lots of girls because I was that good. She didn't believe me when I said she was my first lol
But yeah don't over think this man. You will feel the vibe aswell when you know she wants it. Hope this helps!