Yeast infection

I just need some advice and help right now please no rude comments. So I have a really bad yeast infection I’m 15 and i ask my mom if she can help me buy Monistat she says no she won’t help me. I have no other person I can turn to. I’ve gone to planned parenthood what they prescribed me didn’t really help. I was thinking of putting a tampon with apple cider vinegar. I just feel really hopeless right now.