I am delighted with your progress and your willingness to challenge yourself. Nevertheless, I am skeptical about the logistics of walking across the country, and I worry about your safety. Will you have a buddy following you in a car? You would have to walk along interstates or turnpikes, which I don't think is allowed, or at the very least, safe. For example, I live in the suburbs, and if I wanted to walk into the city, I would have to walk along a highway, then cross a toll bridge. Most of the country, even in heavily populated states, is in the middle of nowhere. Walking 4 miles a day sounds like plenty of exercise, as your results have already proven. Have you considered jogging? Perhaps you could travel by car, and along the way, find parks and walking trails along the way. If you live near a large city, perhaps you could walk every street and avenue. I hope this is not sounding too critical, but I don't want to see you get run over or attacked by rednecks.