Yeast infections/BV/UTI after sex

Sooo every single time I have sex I get either a yeast infection, BV, or a UTI! I’ve had one sex partner for the past 10months I use really safe lubes like glycerin free and all of the above! I wash with non scented soap and cool water! I don’t put any lotion or anything that could throw my ph balance off! I pee before and after sex and I CANT GET A F*** BREAK!!! I get them every single time! I keep going to the doctor and they keep giving me antibiotics and over the counter medicine like monistat I don’t know what could be causing it! My boyfriend washes himself with MY soap before sex and he doesn’t even finish inside just in case that was the thing throwing my ph balance off! We even bought condoms that are safe for women just in case maybe the skin to skin contact was causing it and nothing! What am I missing? What do I need to do?! Please help me😭😭😭