I need help with pms

So I went on the shot like 3 years ago because my pms symptoms involved me throwing up almost every month and the backpain was seriously rendering it hard to move. It worked great, but we lost insurance and a few others things so I got off it, and now my as my period gets more regular the harsher symptoms are coming back.

I have school tomorrow, but I haven't slept all night because I've been so nauseous. I finally threw up an hour ago, and now I can't stop and my back is almost putting me in tears.

Please please please I need any advice I can get, I have no idea what to do