21 and i cant get horny?!

6 months ago, I'd rip my mans clothes off like I was a tiger about to devour him. Now, even if I tell myself I want to have sex, I can't. I'm dry. We use lube but he doesn't like the way lube feels. He wants it to be natural, and I can understand. Sex with him is very enjoyable. Best I've had actually. I just can't get turned on... Literally if he is eating me out I'll get a little wet but the minute that's over I'm dry as a bone and we have to use spit or lube just to get him to go In me! I just am at a loss. I really want to please him tonight but I don't know how to fix this. He will be home in a few hours and I want to be ready for him.