Burning/itching after sex every time

I've been with four partners in my life. I'm currently with my boyfriend of one year. Everytime I've had sex though I get itchy and I have a burning sensation down there. I've been tested for STDs twice (both times were negative), and I've visited my Gyno 5 times. I've been diagnosed with a yeast infection back in August of 2015 and December of 2015. I was recently diagnosed with Bacterial Vaginosis in April after my boyfriend came down to visit from college. My Gyno prescribed 5 days of antibiotics but the symptoms came back. They come back everytime I have sex, plus my bottom is itchy from trying new things with my boyfriend and I can't get it to stop. This has never happened before when he and I have had anal. Apparently I'm allergic to latex condoms, certain soaps and lotions. I'm not on any birth control and my boyfriend can't stay hard with a condom. How do I prevent having an itchy bottom and vagina, and how can I have safe sex with my boyfriend if he can't stay hard and my religious parents won't allow me to get on the pill? Help please🙁