On top?

I just think our relationship is so adorable, and I'm really happy with it. The only problem might be is how inexperienced I am in bed, and he is not at all. I really don't think he minds, he even said he loves that he gets to teach me and see me get better.
But I've been wanting to try cow-girl for a long time, and when I finally get on top - it's harder then it looks. I can't move right, get a motion, I don't feel anything, and I need to sit up or its  jamming my cervix... he tries to guide my butt, but It just doesn't happen. I felt so out of place up there lol. Even though I was fumbling around he was smiling wildly at me, so maybe I didn't do too bad. But idk.