The intensity of the situation can change your breathing pattern. If you remember to breathe and not hold your breath you get less headache feelings. I too suffered like you, and although it is hard to think of much at all it does make a difference. My partner noticed I got tense and would almost hold my breath before climaxing, he would get me to relax and breath more deeply and things improved. I sometimes still get headaches and some dizziness but enjoy myself without painkillers.
Hello,
Many women have menses that last more than five days with varying degrees of the amount of flow they have over that time. So yes, that is a variant of normal.
Headaches after orgasm? I don't know, maybe it is the intensity of it. Perhaps you should try taking tylenol or motrin prior to self pleasuring and see if that helps.
Best regards,
Dr. Downing