Always Dry....

I'm always dry down there.. Like. Always. Even when I'm super horny and my bf and I are getting frisky, I get frustrated. I get wet after he goes down on me, but it doesn't last long and then we both have to keep applying lube or spit to keep it moist so sex is pleasure able. I'm so frustrated because I feel like my bf thinks he's not enough. He drives me so crazy sexually and I want him so bad all the time.. So what's going on? It's not just during sex either.. I'm dry pretty much all day everyday. Am I not hydrating enough? How do I fix it!