help!!

okay so i get really frequent UTIs and i don’t know what to do. i pee after sex, i change my underwear constantly and try to not wear any(sometimes), i only drink water with an occasional soda, i don’t touch myself and like i don’t know what to do anymore. i’ve tried the UTI pills, they don’t work, i’ve tried cranberry pills, they didn’t work. what do i do. if i tell my mom she will automatically assume im having sex and just get angry. pls help