Changes in periods?

When I get my periods, they seem to only get worse and worse. I notice my periods becoming more painful when I turned about 18. I had major cramps, lots of blood clots, and my blood is always bright red. Now that I am 20, my periods are unbearable. As soon as my period comes, the cramps hurt so bad I can barley walk! My period is way heavier with nothing but blood clots. Ladies, what do I do?!?