How about taking some programming courses and starting a new career as a programmer? The job is low stress and very rewarding and stimulating.

If you love nature, you could also think about anthropology, geology, archaeology, environmental engineering fields.

There are also a lot of schools nowadays offering Adventure Leadership courses. You basically becomes a trained guide and take up clients on hikes and climbs. I know a guy who’s in this program now and it’s really the coolest thing ever.

Lots of things to experiment with here. Just do some research.