Early menopause or something more?

Patient: I am 46 and was treated with radioactive idodine for hyperthyrodism about two years ago. Since the treatment my periods have gone from being 4 days duration every 25 days to 7-10 days in duration every 30 days. They have increased dramatically over the last 3 months to being extremely painful and clots are continuousI have only had a 4-5 day break in between.Bloating and severe back pain radiating down my leg are the norm. I have had a history of chocolate cysts before my children were born (yougest is 18 now). Is this normal pre menopausal symptoms or something more?