Im going to pain management in the morning to get a shot in my back what should i expect to happen and how am i gonna feel after, and does it hurt?

Depends: It would be nice to know about your problem in more detail and also about the shot you are getting. There are different medications introduced for different reasons. You may experience from very little to quite a bit of pain. Sometimes it takes a little while for the shot to start working and you may end up having more pain at first.

Aftereffects: "a shot"! this is likely an epidural injection where he/she injects a steroid into or onto the area that is damaged. If successful the pain relief will be quick due to the local anesthesia, then may wear off for a few days until the steriod effect come in (5 to 10 days). Worst effects i see are recovery from anesthesia, which is variable, but may take a few hours to wear off.