As somebody who sits at computer all day, who is too cheap to buy equipment, too embarrassed to be seen exercising by others, and who hates the idea of devoting an hour a day to physical agony, this appeals to me.
1) you have a serious, unaddressed medical condition (please seek help!)
2) you're trying something far beyond your normal activity level. There's no rush, work up gradually and your body will adapt. If a walk around the block is a challenge, start there. Repeatable training sessions over time is what makes change, not beating yourself up in the name of 'health'.