My old boss had something very similar it was on his L4 or L5. He decided not to listen and pushed it. He pushed it too much and he ended up having to get surgery. After a few weeks of break he could still feel it so when I went in he would basically tell me what to do and watch cause it would hurt him to bend over (we were doing hardwood flooring). I think the best thing to do is talk to a doctor and find out what your options are. If you really want to keep lifting, then get yourself a belt, that should take the pressure off of your back and put it more on your whole core.