What could the issue be ?

So I’ve been getting recurring yeast infections for a year and my doctors say that I’m perfectly fine it all started after I got off of the implant. I stopped having periods and I’m not pregnant So my doctor ran my blood and told me I had high cholesterol and that I was pre diabetic which I have gained about 75 pounds since being in college. I go to school in Louisiana and I’m from Missouri I started noticing I never get yeast infections when I’m at home but when I go back to school they come back...