I’m only 21 what is happening

So I’ve had some problems in the intimate area. Sometimes it’s too dry down there. Sometimes it’s fine when we start then ends up drying up? It’s not that I’m not happy or anything. It hurts and it’s uncomfortable and upsetting. He tells me that it’s okay but shouldn’t this not be happening? Any ideas I don’t know if it’s strange enough to see a doctor honestly. I just need advice please.