Kidney infection

I’m literally in the worst pain of my life! I spent the day in the hospital dealing with severe stomach pains and nausea and vomiting. Long story short at 27 weeks exactly I was diagnosed with a kidney infection, uti and Hydronephrosis. They gave me iv fluids, an antibiotic through an iv and I’m taking an antibiotic at home. I see my OB for a follow up in the morning but I’m experiencing the worst pain again. It’s gonna be a rough night. Any suggestions for back/ kidney pain?