What Causes Nausea And Vomiting Along With Back Pain During Menstruation?

I am a 22 year old female, I have had very normal cycles for 5 years. But for the last 2 months they have changed drastically, for the first day I am so nauseous I have to lay in bed flat on my stomach all day and if I so much as turn over I throw up immediately. And my back pain is so bad I thought I had another kidney stone. I have no appetite for the remaining part of my cycle, and no energy. During my normal cycles I don t bleed at night ever and I don t ever have cramps at night, and these last 2 cycles I get more cramps than during the day in my ribcage area which never happens, and I even bleed more at night, and get fevers. I am just scared that they have changed so rapidly and badly