What Causes Heavy Clotting, Tiredness, Headaches With Hot And Cold Feelings?

Hi my name is Laura and I have been on my menstrual cycle for 3 months now. Sometimes I bleed out blood clots the size of o half-dollar bill, I feel tired alot, get hot and the next minute I feel cold, I get mad easy, I get headacks, I feel dizzy at times, and I want It to stop. I had twins 10 years ago. The nurse who was on duty the day of the birth said I lost alot of blood. The doctor gave me thet dapo-shot (A birth control). Six weeks later I got my tubes burned. One year later I started my proied. It was so bad I had to ask one of my friends to take me to the hospital. I have been going to the doctor for this. They just did a pelvic x-am last week. What is going on with me?