I Had Complete Respiratory Failure A Year Ago..I'm On Oxygen

I had complete respiratory failure a year ago..I'm on oxygen at night but I can't seem to get my strength back. I also have a pacemaker and defibrillator. The wheezing has never stopped since I was on the vent. There are times I get the same strange feeling in my chest that I had moments before the respiratory failure. Could there be something the Des are missing?