Yeast Infection Tips??

Hey ladies! I need some advice and some of your best tips on how you avoid or get rid of a yeast infection fast... I’m 17 and I get them often and I don’t know what I’m doing wrong?! I wash my body at least 3x a week, I pee after sex I just don’t know if there’s more I should be doing now that I’m older? Please please help I’m in a lot of pain and it feels very uncomfortable I need help