maybe there's a neural aspect to this. seems to be going on a little bit longer than one would expect for a "normal" hamstring tear..

have a qualified physio assess your lumbar spine and neurodynamics in detail. by this i mean slump test, straight leg raise etc and see what comes up.

you could google straight leg raise and have someone try it on you either if you cant see a physio. see does it or the slump reproduce some of your symptoms.