vaginal pain during and after intercourse

I dont feel any pain until he is about an inch inside of me...This pain only occurs if we have had sex a few hours prior. I feel the pain inside my vaginal wall, not the outside. It feels like a tear or cut. I went to the doctor a few times and was treated for a yeast infection. We use tons of lube and sometimes lube helps it subside. I don't feel much of the pain if it's the first time we're having sex in a few days. We have tried about 3 different kinds of lube too. It cant be dryness or allergy. Once he gets it all the way in I am ok. If he pulls it out and then puts it back in, it hurts. It feels like there is just one spot that he has to pass then it's ok. The gyno tells me I am fine. No infections and I dont have any tears... Is my partner's penis to "fat" for my vagina entry?  He is larger than the last/first man I've been with. This is so frustrating. We have to usually wait 2 days in order for my vagina to be fine to have sex again. Then I am sore again immediatley after the first time we have sex. I can't have sex more than once a day with him or I am way too sore. Help me.. please. I read online that taking a fish oil supplement may help, has anyone else experienced this ??