Irregular and prolonged heavy periods.

Earlier this year I was facing the problem of prolonged period which was like spotting only and too dark in colour. For which I have consulted with Dr. and was suggested hormonal pills to regulate the same, also thyroid test was conducted and found that TSH level is on higher side. Accordingly thyronorm 0.25 mcg was started. After taking hormonal pills period/spotting get stopped and during non-pill day I had 3 day periods. These pills cause fatigue, dizziness and irritation. I myself stopped taking these pills after two months and get thyroid test also which was normal. After this there was a gap of almost three months for next period which lasts for almost a week. Again I'm having periods after 3 months gap but this time it's like not going to stop. It's been 20 days and period is like normal to heavy bleeding with large size clots everyday.