I like that you reflected on not just your pain, but that you are now experiencing something that others may experience on a daily basis.
I have had the fortune of a great chiropractor (people have polarizing opinions about this work). I have had prolotherapy on my back (@halo also covered this recently). But I think finding out the root cause for the pain will give the answer you need.
My dad has hurt his back just twisting to reach something and has had times where he needed to go to the hospital because he could barely move.
A nerve block is not a long term solution, but may provide some relief (and is not addictive like pain pills can be for some).
Strengthening the back muscles as you have done should help. (I tore ligaments in my back and as you know, the back recovers slowly and everything you do affects it).
I would get multiple opinions on your pain, because you may find a completely different therapy that will work for you that you had not thought of before.
Thanks Ben. In the past, I would just rest and try to get out moving again which seemed to help with the upper back issues (root cause: slipped disk injury in high school). That usually works and would only give me a problem a couple times a year or so. This was the first time I had sciatica / lower back pain. After many weeks of PT, I'm thinking the same solution (run, exercise, rest, etc) may be the way to go yet again. We'll see. If it continues, I'll definitely be getting additional perspectives and opinions.
While not inexpensive by any means if you have not looked into spinal decompression, that may also be something worth considering. Hell maybe you could write about the experience and get paid to do so to cover some of the cost if your insurace does not.