I think you should get a coach. It is likely that you can train with barbells and that doing so will be good for you and your back. It sounds like you have a fractured piece of the annulus fibroisis floating around in there, which worries me a little. At the end of the day, you need to pick things up off the ground. There is some weight that is appropriate for you to do that. A qualified coach will be of much more use to you than I am on the Internet. Where do you live?