Only your doctor can help you decide when you are ready to return to work, so the first thing to do – if you’ve not done it already – is have a talk with him or her. Discuss your pain, the type of work you do, and your fears about re-injuring yourself.
Something that is important to understand though, is that often the fear of hurting yourself again or more actually can work against your back healing properly. This fear of pain, often called fear avoidance, is not uncommon and has been studied by researchers. If this is what is holding you back, your doctor may be able to recommend a rehabilitation program that can help your back get better and help the way you think about your back and pain at the same time.