My 70 yr old husband hurt his back June 3 putting new windows in the house and could barely walk with similar symptoms you described. MRI indicated disk bulge at the L4-5 and Spondylolysis at L5-S1. Our doctor recommended physical therapy and said 80% of the time it will get better on it's own with therapy & rest and that surgery wasn't always the solution.
Hubby thought this can't work, but went anyway. He was amazed at how much better he felt after a week and was able to get rid of the walker he was using after the month was up. He did the therapy for 1 month and decided he could do the rest of the exercises they gave him at home. After 4 months now, he is pretty good, except when he tries to lift things too heavy and strains his back, then it takes him 3/4 days to get back in shape.