depression and COPD

I was on oxygen for a couple of years. Started walking 3 to 5 miles a day. Not only did I feel better and have more energy. When I went to take my yearly 6 minute walk at the VA, my O2 level didn't drop below 92, so I was taken off oxygen. A couple of years later I fell down the stairs at home, and broke my neck. Since then I just haven't had the motivation to continue exercising. Been seeing a therapist and shrink for some of the the thoughts that I was Having. Really need to start back into my walking routine