Tips on riding my husband?

I hardly ever go on top because I don't know what I'm doing and it's kind of hard on me. I already have bad hips, so it gets painful quite quickly. I just feel so awkward on top. The most I can do is rock back and forth, but that makes me finish too quickly.

So usually he's on top or going in from behind with me over the bed. I know he wants me to go on top, but I'm not comfortable doing so. Any tips?