23 yof with hot flashes, osteopenia, thinning hair and now ovarian cyst... Thyroid is fine... Any ideas? Not on bc

Several issues. There are several areas that should be explored with your doctor. First, get evaluated for a hormonal imbalance. With thinning hair and an ovarian cyst, the diagnosis of pcos is possible. The osteopenia is concerning because of your age but can be caused by some sort of nutritional deficiency, such as vitamin d deficiency or celiac disease (causing difficulty with absorption of vitamins).