Did you know there are different types of PCOS depending on your symptoms and hormones? I have Insulin Resistance PCOS (the most common) and Insulin Resistance was the most disruptive symptom I've had. So the following advice is geared towards that:
1) Honestly cutting out added sugar and replacing it with stevia (even minimizing products I buy with added sugar)
2) Switching almost all sources of simple carbs to complex carbs
3) Eating/drinking REGULARLY throughout the day to prevent hypoglycemia
4) Exercise and weight loss (or gain if you're underweight). ☹️ Sorry ik this one is super freaking hard and shoved in our faces all the time, but, truth be told, I have so much more leeway now to break some of the above "rules" than I did when I weighed more. The body just gets more efficient when it's at a weight that's naturally ideal for you.
5) Oolong Tea and teas between meals in general to help with #4! (although please use responsibility it probably is the reason I have iron deficiency anemia now). This was super helpful for my weight loss. I would drink about 4 cups of tea a day, 2 of oolong and 2 of any other mix of tea (non-herbal). This helped tremendously with cutting out sugary drinks and filling me up with something that wasn't "food" but would hold me out between meals during weight loss. Oolong specifically acts as an appetite suppressant which helped me a ton not end up in hypoglycemic episodes between meals lol. This was before I knew I had PCOS and the effects of caffeine on PCOS so please be careful not to overdue it. There were very few times I did overdue it tho but personally found anything over 2 cups of non-herbal teas are probably not the best for you so do your research there.
I am currently experimenting with supplements so I'm not much help there. Also trying to see if I get my period back after coming after BC so also no help there. I hope the above is useful to you or anyone else! Good luck!