Disturbed Menstrual Cycles in Young Female
Here are some common causes of irregular periods among young women. You had got some relief from Diane-35 (cyproterone acetate and ethinyl estradiol). Cyproterone acetate is a progestin and Ethinyl estradiol is the estrogen. First, it’s not a very safe drug and it’s good that your doctor had stopped it. But your change in symptoms point towards some hormonal disorder.
You also mentioned that you have hypothyroidism. It is well known fact that thyroid disorders may manifest as irregular menstrual cycles in many individuals.
So it would be a good idea to consult an endocrinologist for thorough assessment for hormonal imbalance.
You may also need a detailed gynecological exam to rule out such problems as PCOS. There is some link of polycystic ovarian syndrome (PCOS) with higher body weight.
Your weight may also be linked to underlying thyroid problem. You should consult with an endocrine specialist about all these possibilities.