Recurring UTIs?

Has anyone had recurring UTIs after sex and if so how do you prevent them? I’ve been taking Macrobid (nitrofurantoin) for a few years now after sex and it’s the only thing that’s helped control the UTIs 100%. But unfortunately it’s very expensive now with my new insurance and I’m not sure what to do now because I can’t afford it. I’ve tried cranberry juice and pills and peeing after sex but those don’t help.