My left leg has given out several times in the past 3 weeks. Huge disc problems after injury!

Had 3 work injuries in same lumbar region, 3 surgeries on right side lumbar L4-L5 and L5/S1. Now the left side is acting up and shows major problems on new MRI. Disc bulges in all levels resulting in spinal stenosis. There is also a damaged nerve at L4-L5 right lumbar region. Also have chronic pain if I walk or stand more than a few minutes. Sleeping is very difficult and I often wake up crying with hip pain, leg pain, etc. The most frightening thing is I will be walking and my left leg will just not be there and I will go down...on my hands and knees. It is happening more often each week.