Is it him or me?

I’ve been in a new relationship for 7 months now and I’ve never had so many yeast infections in. my. life. I don’t know what to do, I don’t know if it’s me or him. If i forget to pee one time after having sex i’m already doomed to an infection and it’s frustrating having to go to the doctors and buying otc treatment. I’ve had other partners and this has never happened. I’ve had a yeast infection before but never as severe as the ones I get now. I just don’t know what to do.