I Injured My Back Lifting Something, I Have Been Stretching

I injured my back lifting something, I have been stretching and pool therapy, it seemed to get better the excruciating pain went from an area of mt glute to down my leg. 2 months later I was feeling pretty good until I ran across a parking lot, and it was back 2weeks went by and now the pain went to a more numbing feeling down to the lower part of my leg. Is this to be concerned about? will it heal with the physical therapy?