Long period, constant cramps, lower back pain, spotting, nau

I had my period for about 7 days, then after a night of drinking, I woke up with a hangover. I was vomiting and felt nauseous the whole day and just didn't feel right. The next day my period came back and I had the WORST cramps in my stomach, legs and lower back I'd ever had. The bleeding subsided that day. It's been 4-5 days and I'm still cramping and am in extreme pain. I can't go a day or night without Advil. The pains in my back is mostly on the right side but my lower abdomen is cramping on both sides. I don't have very good insurance so I'm trying to hold off on going to the doctor as long as possible. Can anyone help me with this?

Thanks!!