This is occurring due to PCOS
. Hyper insulinism is causing changes in other hormones leading to absence of menses. You have not mentioned if you are on metformin
now. If yes maybe you need to step up the dose. If you are currently not on metformin, better start it.
You must try other helpful measures like regular exercises, especially of the abdominal muscles like abdominal crunches and no simple sugars in diet along with weight loss
Hope this was helpful. Have a good day.