Oral sex

Hello! I need some advice. Whenever my boyfriend goes down on me, it really hurts. We've tried everything. I've communicated with him like telling him to go to the left, up, harder, slower etc. But nothing works. I'm starting to feel like something is wrong with me and I feel really bad because my boyfriend thinks it's his fault. I just want to know if there's any to make it feel better.

Thank you very much