I used to hate sunny days when on my period because walking to class I would often very nearly faint/pass out.
I would feel nauseous and very weak. I used to have heavy periods with clots also.
Then I went on the pill and I no longer have any problems like that.
Did the pill fix your problem at all? How long have you been on it?
Since I went on it my period is almost half the length and probably 2/3 as heavy. I also can skip my period most of the time.
I saw a gynaecologist about 18 months ago and told him my symptoms. I had chronic pelvic pain and had started my period at 12, like you, and didn't have any pain or discomfort. By the time I was 18 my periods were unbearable, especially moving to university and having to looking after myself.
Based on (these and other) symptoms he said I would have endometriosis and that is what I skip my periods for.