My ME/CFS was triggered by a combination of viral infection and various other life stressors. I recovered by removing all the stressors (including quitting my job), then gradually building up my life again with positive uplifting activities and goals. Somewhat similar to Fred Friedberg's protocol.

http://www.cfsselfhelp.org/library/fred-friedberg%2525E2%252...

https://forums.phoenixrising.me/threads/dr-friedberg-intervi...