Most likely a combo of those, and being off work really helps.
Most likely the Dr was just a necessary tool that was able to prescribe the meds for the moment, I don't know that he did much more than that for you.
Seems like he should have done more of some sort of assessment, but some just prefer to rx meds and see if it helps.
Sounds like it helps with the pain and that is good- but for the long term you need a real assessment or evaluation to find whatever the real cause is.
If you want to stick with this dr for now you might ask about a PT referral & evaluation- and see what he says about that?
Oh,
How long are you to be on the meds he rx'd?
If a short term "test" and then a follow up appt to see how you are doing at that point- I suppose that is standard procedure.

here's info on the Medrol-
http://www.drugs.com/mtm/medrol.html

keep up with the posture and things you are doing to heal.