UTI HELP HELP

Okays so. Ever since I've been sexually active I've been plagued with constant uti symptoms. Sometimes not bad, sometimes unbearable. I've been on a variety of antibiotics and had multiple cultures done but nothing seems to work. I've taken d mannose supplements, and probiotics, I always pee after sex and have a wash up, but yet that doesn't stop them.

Has anyone ever beaten this??

It feels like my sex life is cursed x