What is this discharge?! Help :(

This happens every month like clockwork during my PMS week. My discharge is so overactive, clumpy, I get itchy, and want to change my underwear multiple times a day because of how uncomfortably soggy it feels. my doctor can’t see me for a while, and just need answers now, not later.

I’ve already taken an STD test, everything came back negative.

Would the Monistat 3 day help?