What Causes Leg Pain After Undergoing L5-S1 Microdiscectomy?

I am five weeks out from an L5-S1 microdiscectomy. Still having significant left leg pain, primarily behind the knee and hip and significant foot numbness after walking. Recently prescribed 900 mg per day Gabapentin, taking 800 to 1600 mg Ibruprophen per day. Occasional 5 mg
Norco, 2 PT sessions per week. Disturbed by continuous pain. Surgeon seems very unconcerned. His only comments are that
I have very sensitive nerves.

I'm concerned that more is going on than I know. My left hamstrings are very sore and tight, my left knee is hyperextending in response to significant weakness on my left side, which makes walking painful.
I want to know what else could be going on and if any tests should be done, or if this is the normal course of post-op pain. My orthopedic surgeon is minimizing everything as being normal, but I need to deal with this pain. I am 53 yo and a lifelong inter, runner, bicycler