Experts say that motivation is fueled in some people by a desire for gain and in others by a need to avoid pain. It sounds like the desire for gain is not very motivating for you any more. What if you lost your lifestyle and could not travel anymore and had to take a 9 to 5 in a cube? Would that motivate you?
It also sounds like you are looking to do something that matters - that gives back a little. Perhaps if you set up shop as a masseuse you could work on your sites between clients. This would add structure to your day by giving you an office to go to and a time when you need to be there. I had a 12 hours swing shift job - I was so motivated to get out of that job (avoid pain)that I worked harder than ever. I was promoted to a day shift job and have struggled with motivation ever since. The thing that is starting to motivate me now is that I see retirement is a dismal picture for most people in the States. I don't want that! I want a comfortable retirement (from my working job) at age 50.
Best of luck to you. I know you will find your motivation.
If you decide coaching struggling webmasters to $300 per day will motivate you...sign me up! :)