Why are the lips of my vagina itching? It is long but it gives background that helps explain why I am confused

About 2 to about 3 weeks ago or so, I took care of a yeast infection that I had and since then I haven’t had any problems. Last saturday my boyfriend came back from a one month work leave ( he was in texas helping with the fire) but since he has been back we have been having a lot of sex. About 2-4 times a day. I don’t regularly shave my pubic area but i thought i would do it as a treat for him. However, when he pulls out (I am already aware that is not a safe form of pregnancy protection so please don’t lecture) and cums onto my mons pubis area I think it irritates the area because the area will start to itch quite a bit. It that area will itch at other times as well but the past 3 days or so, the lips of my vagina have been starting to become irritated, itch, and become quite sensitive. We haven’t slowed down on the sex because when we do start to get going it doesn’t itch or be irritated (my clitoris is still sensitive but that makes it all the more fun) it happens after or periodically through out the day. I was hoping to know if this has happened to anyone else and if they could possibly give me any information. telling me to go to the doctor because even you don’t know what is going on does not help me because if I do not aquire any help I will end up going. I have done a little research of my own and some are saying it is a yeast infection but I find that highly unlikely because I just got over one and I express no other symptoms of a yeast infection besides the irritated libia. Another source said it may be an allergic reaction. I am allergic to almost every type of animal, many pants and pollens and believe it or not about 20 different foods (beef, poor, shelfish, garlic, onions, tomatos, ect) so this sounded like it could be a possibility but I wouldn’t know what it is that i am allergic to. I have heard that some people are allergic to semen but I don’t find this likly because we have been engaging in intercourse for about 5 months now, same happening of him pulling out and cumming on me, this only just recently happend. He got a new shampoo that he uses that conains wheat, avocado, and soy, all three I am allergic to. So my real question is is am I just having an allergic reaction to him and his men, his shampoo because of the ingredients, could my yeast infection have come back, or is it possible that we are just having enough sex that it is causing my pubic area to become tender?