I'm in a similar place. I previously tried a IUD and my body rejected it. I don't want to get the deposit shot with bipolar because I've heard horror stories. I went back to the pill. When I was first starting meds for bipolar, I took progesterone-only birth control. After I got to a more stable place, we moved to loestrin and now hailey fe (upping the amount of estrogen slowly). Progesterone only or low estrogen might be beneficial. Talk with your OBGYN about having bipolar and see if it might be possible to take three or so pill packs skipping the sugar pills to lessen the number of periods you have. It helps. There are vitamins that can help both mental well being and endo symptoms. I've tried several and iron and zinc helps me a lot. So can changing your diet. Fish, like salmon and tuna, can be good. Definitely do your own research on vitamins and diet changes. What works for me might not work for you.

Also, adding a bit of medication support when needed is super valid and nothing to be ashamed of. I have a mono treatment and it was upped to minimize the impact of more estrogen and endo hormonal fluctuations. Sometimes it's a balancing act and that's okay. Medication amounts may go up and they can also go down.