I'm in pain, doctors dont know why!!?

i'm 18. i had an IUD put in March 8th (Monday), it was very painfull because i never had any children and my cervix was very tight. That weekend the pain was still there and getting worse. By tuesday my right side was hurting so bad i couldn't walk and had to be taken via ambulance to the ER. They did a cat scan and found that I had an abnormally large appendix and gall stones but there was no inflammation so the surgeon doesn't believe thats what is causing the pain.Wednesday the removed the IUD. My blood test shows nothing, white count is normal everything in my blood tests came back normal. The pain starts just above my last rib and goes down to my hip, it branches inward about 2 inches and it goes towards the middle of my back about 3. I can barely walk let alone sit up straight. I dont eat much but never really have. and lately i'm a little gy but not bad. Please help me