Never reach my O!

Does anyone else struggle with the the issue of never reaching their climax? I am 22 and it has made me extremely self conscious to even consider hooking up with a guy anymore. I feel that the older I get, the guy wonders why I don't know how to or what the problem is. As time goes on it just makes me freak out even more. I'm not sure what to do. I have read that many women have the same problem. But I've been with guys that say I'm the only one they have been with that couldn't and it makes me very insecure. Help!