I know how you feel, I have a bad back anyway and this is my 4th op (all others were medical) I always get really bad back ache due to how I lie or sit. The worse bit is a major pain in my shoulder due to the anasthetic, don’t know why but its always the same and it kills. Worse part now is I can’t raise my arm to stretch it!!!
if it doesn’t improve don’t put up with it go and see someone as it will only get worse, make sure you stand up and walk about a lot and try stretching it out. If you have any of your pain killers left it might be worth taking them xx