Problems with oral sex

I love my boyfriend and he likes to do new things, which always keeps things interesting. He like oral, both giving and receiving. However, I guess I'm not so much. I love it when he likes to give it to me but I get problems done there when he does. My vagina stings and it hurts later, sometimes not too bad to nearly doubled over in pain not wanting to get out of whatever position I feel comfortable in. I can't even handle giving him oral then having sex later. Like he would have to put on a condom if I give him oral before we have sex or else I'm in pain. It's like my vagina doesn't like any bacteria that's found in a mouth or else it goes into antibody attack mode down there! Is there any tips or anything to help with that? Am I going to have to just deal with it? Has anyone else had this problem?