Drying up mid sex

A

Recently, my boyfriend and I have been having sex and I will be wet during foreplay, but when it comes down to having sex, I dry up and it just hurts to have sex because I’m dry. Do you guys have any solutions or ideas why this might be happening and what I can do to fix it. I’ll be horny and wanting to have sex, but it just doesn’t seem to work. Please help. 😩