Condoms Keep Breaking?!?!

My boyfriend and I always have to use protection because I am not on birth control. He applies condoms correctly but sometimes the always keep breaking. It usually happens if im too dry but i can't really feel that. I don't want to get pregnant and can't be on the pill due to health problems. any advice? We have tried many different brands, same thing always happens. i dont know if its because we go for a while. Or if we are being too rough. If anybody had any ideas I'd appreciate it thanks!