Just to let everyone know that I'm doing better. My energy level is back and I have less stiffness. My neck is better. I guess those 100 sit-ups I did on the ab rocket were not done properly! I will definitely pace myself this time around and only do weight-bearing exercises. I do have an in-ground heated pool which I was in yesterday. I know this is the best exercise!
I'm walking better but I have a lot of pain in my left foot. I went to see a foot specialist who recommended some custom moulded foot orthotics and a good supporting shoe. Although my foot x-ray looks great except for a bit of arthritis, my foot arch totally collapses in when I stand.