Your problem is that you were happy as a child and unhappy as an adult. That's a personal problem, and has little to do with rural or urban living. As other commenters have pointed out, you can most likely afford to buy a farm if you really want that lifestyle. I suspect you don't, because it sucks major ass to have to do manual labor all day, to eat almost entirely the same things and see the same people for decades on end, and to choke off your access to most of the joy and beauty in the world.