Feeling Pained

I was in an unhappy marriage for 5 years with a narcissistic husband who never liked intimacy. After we split I met a man who I’m currently dating and he is very affectionate and kind and enjoys being intimate with me. The only problem is that he is a bit aggressive when it comes to oral sex. It’s actually painful and causes me soreness for days after. I don’t know how to tell him without sounding unappreciative as he quite enjoys giving oral sex. He can spend hours down there and never complains. But I’m just not enjoying it and I do not ever get off from it because it’s just too painful for me. I’m so scared to hurt his feelings. He has never asked me to return the favor either. I think there’s something wrong with me though as the only way I seem to get off is when I’m on top now. Wondering if there might be some damage done. Need any advice I can get.