My daughter had CFS. It lasted 18 years. I know that is not what you wanted to hear. The good news is it did go away. She needs to be very careful to not overdo, but she has done things like backpack the Pacific Crest Trail, 286 miles from the Columbia River almost to Canada.
What treatments have been helpful? She takes modafinil or brand name Provigil. She takes a smaller dose than offered. Smallest tablet offered is 100 mg. 70 mg/day is what she finds helps her greatly. If you try modafinil, I'd suggest you start with something as small as 12.5 mg/day (use a pill splitter) or 25 mg/day and stay on whatever dose you are trying for a couple of weeks before making any changes, unless even that amount is too much. But I'm not a doctor, so don't go by my suggestion w/o seeking medical input. Good luck to you.