start-up

The very idea of getting out there and doing some sort of exercise, some sort of physical activity depresses you. It is contrary to your beloved couch-potato image. Yes, you'd look like a bowling ball in one of those spandex outfits.
So skip it. Go for something closer to home. Comfortable, loose fitting clothes. Forget the car keys (that could be traumatic in itself but nothing is easy) and go for a walk. Go for something manageable. A few blocks will do for starters.