The ultimate resource for dealing with fatigue is the book called "Energityvene" ("Energy Thieves") [1] which is only printed in Norwegian. It covers pretty much every single fathomable situation in terms of people dealing with fatigue, such as disabled people and high-performing professionals. It covers all types of fatigue, whether it be physical or mental. Most importantly, it gives actionable solutions for all of the above categories for people in various situations.
Unfortunately, this is the only source that covers it from A to Z. The book helped me tremendously and was life changing. I found it by searching across the web, using key words, and found a bunch of useful Norwegian PDFs, such as these [2][3]. Since it was mostly all related to a book in Norwegian, I found a bookstore that sold an eBook version of "Energityvene". I converted the book to a .docx file using Calibre [4], and then I uploaded it to IBM Watson Language Translator [5], and had the .docx translated to English. I then read it and it changed my life.
Also, chronobiology [6] is a big deal and makes a huge difference, if you understand it and study it. Knowing your chronotype (circadian rhythm pattern) and calibrating your life around it makes a huge difference. Here are a bunch of useful PDFs about chronobiology [7]. Interestingly, I use light therapy (different sorts of therapeutic lighting) calibrated around the time of day, for my chronotype, to manage my energy levels consistently, so my circadian rhythm stays the same. So, I use a wake-up light (to wake up in the morning), a special light at my desk (mid-day), a sundown lamp (during dusk/evening), and night-time lighting (no bright lights). I monitor the light levels I am exposed to throughout the day (lux levels) so it is a precise and prescriptive amount of light. With respect to finding your chronotype, you may need an actigraph watch to determine your chronotype. The Geneactiv actigraph watch does this, and also measures your lighting levels [8]. It costs around $200.
You also need to practice resting, just as hard as you work. Figuring out how to do that is hard if you have a strong type A personality, but you can do it. Be creative.
Sleep is critical, and is unfortunately extremely underrated. I also record my sleep every night with an OpenBCI EEG recorder [9], using 16 channels. It is effectively a home sleep lab [10]. When I wake up in the morning I run scripts (mostly from GitHub) to see how well I slept, and also to see the sleep staging patterns. This also helps me see if I am going to get out of my circadian rhythm.
[1] Energityvene: https://www.goodreads.com/book/show/34138256-energityvene
[2] DuckDuckGo Search-filetype:pdf "Energityvene": https://duckduckgo.com/?q=+filetype%3Apdf+%22Energityvene%22...
[3] DuckDuckGo Search-filetype:pdf "Energityvene" site:kognitiv.no: https://duckduckgo.com/?q=filetype%3Apdf+%22Energityvene%22+...
[4] Calibre (Software): https://calibre-ebook.com/
[5] IBM Watson Language Translation, Translating Documents Information: https://cloud.ibm.com/docs/language-translator?topic=languag...
[6] Chronobiology Information: http://www.chronobiology.ch/
[7] Peer-Reviewed Chronobiology Journal Articles: https://duckduckgo.com/?q=site%3Achronobiology.ch+filetype%3...
[8] GeneActiv Actigraph: https://www.activinsights.com/technology/geneactiv/
[9] OpenBCI Information: https://en.wikipedia.org/wiki/OpenBCI
[10] Home Sleep Lab Information: https://www.spisop.org/openbci/