Why can't I finish?

When having sex, I have a really hard time getting wet. Trust me, I am definitely turned on, but I can't get that wet. When I do get wet, I have a hard time orgasming. It's really frustrating because my boyfriend finishes every time, and I just want to be able to enjoy my sexuality, without worrying about hurting him or feeling less than because I can't finish. I'm looking for tips on new things to try in bed, or even just ways to get over the hurdle in my head. Thanks!