The good part of what you’re doing is understanding how difficult it is to find any magic bullets with your health. The bad part is you are still seeking a magic bullet, with geneticists this time. Your body has a million years of experience understanding how to make you feel good (through your genes). My advice is to use that.
Brain fog, low mood, very fatigued and tired…sounds like a dysregulated gut and systemic toxins. The consensus of highly effective doctors who treat dysregulation is to start with detox. Add to that a cleanup of all foods and liquids consumed. A spore probiotic (as Megaspore or Thrive) adds 5 or 6 keystone strains that help balance all the other thousands of gut microbes. Also taking a soil-derived, scientifically-backed mineral supplement like Restore helps. It has been shown in lab studies to strengthen tight junctions in the gut wall and rebuild the firewall against toxins entering the body. Doctors with more to say: (Dietrich Klinghardt, Zach Bush, Tom Cowan, Kiran Krishnan). Dr. Klinghardt would probably put you on a Lyme protocol just to calm your retroviruses that now compromise regular function. Dr. Cowan would probably put you on his supplements to make it easier for you to diversify your diet.
Eating a dozen or more different plants each day (>100 per year) provides the body with what it needs to get back into balance (I eat 40/day). Each person has varying tolerances for them, so you need to be vigilant to find what works. The difference between bad and good health is enormous so rewards more than compensate effort. Each plant adds its own adaptogens which are chemicals that the plants generate to cope with their environment. By eating them, you help your body provide similar protections. Plants exposed to a crisis (drought) may have too much of an adaptogen, so surprises are not uncommon. High doses of vitamin C, though, can be used to donate the electrons needed to neutralize anything toxic (Dr. Thomas Levy), since all toxins exert their damage by stealing electrons from healthy cells.
My advice is to get diversity in your gut flora, so your body has what it needs to do its thing. The body is smarter than a team of the smartest doctors so give it what worked over the last million years. Fasting is an important part of that. Time restricted eating is not difficult, and the benefits are quick. With fasting: you remove damaged or senescent cells, detoxify, increase fat burning, increase energy levels, improve cognitive function, and develop healthy inflammatory responses where needed.
What I would not do is listen to the people who now will claim they understand how genes work in a specific case. The past forty years of nutritional guidance could not have been more wrong and the next forty years of genetic guidance will probably be no better. In a culture where information is used to make money, it will be impossible for you to distinguish between good information and bad. I think self-hacking will help anyone who has worked with their own health management as you have. Your body’s responses will help you figure out what you need to get better.
I walk for an hour plus each morning while listening to health podcasts. Over a year, that is over 400 hours. Some I listen to a dozen times. The most important thing I learned is that the body is your best doctor. Shield it from the standard American diet and American medical standards of care, and you will find what you want, and have fun doing it.