Can Long Term Usage Of Pain Killers Cause Any Problem?

hi i have just returned from spain whilst there i was admitted to hospital for the most excruciating pain i have ever felt. I was in 4 days.The xray results show my C67 of my vertebrea has worn causing it to trap my nerve.. I have been taking muscle relaxants, pain killers etc the doctor said this could have happened at any time. What will be the best treatment, could this happen again and how long will i need to be off work as i am a dental nurse which is a very demanding job of which i stand bent over all day to my left when nursing, Could this have have been a contributing facture in my injury? the pain is being maintained by pain killers but when do i stop taking them. I do not ever want to Please help!