Week leg, crushing sound & pain in knee.

I used to run 3/4 kms  everyday for around three years before i developed mild pain in my left knee in the year  2018. Knee pain increased over the time followded by  back pain and weekness in whole  left knee. I stop running, even walking for some months, when i consulted   orthopedics & physiotherapist. MRI report said i have mild PIVD pressing nerve roots, but left knee shows no deformity. After some physical therapy and home exercise and medicine i got some improvement from back pain and weekness in my left leg. Presently i cannot run as earlier, even walking for some distance my left get easily fatigue. Another main concern is that my left knee is not doing as normal as earlier. The Knee has grinding sound like the sound of crushing two hard rocks when bending or stretching. Without  knee support, i cannot walk a quite long. Can I get out of these illness and back to normal  if i get proper treatment from some of your specialist? plz advice me.