Yeast infections!!!

Hi I'm 18 and for the last few months I've been getting a yeast infection almost every single month!! It sucks ass. I've been doing some research of my own and found out that it can be from crazy hormones, it can be fixed by going on birth control but my mom won't let me go on it!! She thinks then I'll be ok with having sex, little does she know I'm already sexually active!! I can't do it behind her back because insurance needs to pay some... What should I do?!