Sir I Am 33 Years Old And I Hav Periods

Sir i am 33 years old and i hav periods problem... my periods are not continuing. I approach gynae doctors but when i take medicines 6-7 months i will be ok but after that same problem occurs. 50-60 days went for periods. I was advised to take novelon tablet but i was ok fir only 6-7 months only. Please advise me what medicine i should take. I hav undergone sterlizatio and i am over weight now.