@DechanDawa , I had a few more thoughts on exercise.

First of all, it makes a huge difference for me. When I stop exercising for a while, I become so miserable and unproductive. I feel nauseated all the time. Everything tastes chalky. ... yuck. When I finally start exercising again, I can really see the difference in my mood. Life really is barely tolerable when I don't exercise.

Second, you need some music and/or a TV. Gyms always have something mind-numbingly boring on TV like CNN business report or something. There is no way I could walk on a treadmill and stare at something like CNN. You need music with a good repetitive beat and no slow spots. Most music has slow spots and that is no good for cardio exercise.