Ways to treat terrible menstrual pain? Is this normal?

Okay, so. My periods are irregular, they come at different times. Sometimes earlier and sometimes later. They're usually heavy and very painful. Right now, it feels as if the pain has found it's way into my lower abdominal, but that may be because I'm putting tension on myself due to the menstrual pain. I need some kind of medication because I'm legitimately groaning in pain right now. Anything that'll help? And you can throw out Advil, Tylenol etc. That never helps. And Midol is expensive, I wouldn't be able to buy any anyway. I have no way of getting somewhere. The pain almost brings me to tears, I can barely walk. What can I do to stop it? It goes on for hours, even days.