Horrible period cramps!!!!!?

So, I'm 14 and and I always wear tampons. I bleed heavy when I have cramps. I've tried over the counter period medicines. I've laid with a heating pad (on the highest temperature possible) for hours. I've taken 30-45 minute (steaming hot) showers. I've done everything I know to do and I'm still close to tears. I've missed school, laid in bed and on the couch for hours (around16 or more) every day while on my period. I've considered birth control, but my dad believes that using it will just give me one more reason to have . If you know what all birth control can do, please include that information in your response. ( I want to let my dad see that part of your response so he may reconsider letting me use it. I'm to the point of breaking! My period isn't always regular, does that have anything to do with it? I don't think so, but I am willing to try or fix anything at this point! I've heard that tampons can and will cause some what worse cramps, but I'll throw up every time I go to pee and have to look at all the blood! I can't wear pads for that reason! I always wear light or regular tampons. I need help very badly! Please help me and ONLY RESPONSIBLE ANSWERS PLEASE!!!!