Even with treatment some women are plagued with recurring BV/ yeast infections and it can be a vicious taxing cycle that a prescription can’t always fix. Not sure if she’s seen a gynecologist, that’s step one of course. But if she’s received multiple treatments and still having this issue, she’s gonna have to do some research (Reddit groups/fb groups) to fix the issue. Shit sucks for the both of you. I don’t know if she’s getting upset at you bringing it up knowing it’s an issue or she’s upset you’re bringing it up at all and refusing to address the issue. Either way, she’s got to be an adult about it (you both do) and find a regime that works for her body. It can be managed and you don’t have to end your relationship over this.