Suggest Medication For Severe Menstrual Cramps

For a week to two weeks every month i wake up in the middle of the night with severe pain (like menstrual cramps but a lot worse). Sometimes they are so bad i feel like im going to faint. This has been happening for a few years but has got worse lately, im 22, 5ft and 7 stone 8lbs. Sometimes i think it has something to do with my cycle as it is normally 1-2 weeks before my period, but as i get so bloated i feel it could be related to my bowels? Please help.