Have you tried goat's milk instead. I think it can be a successful alternative.
Do you think that your fatigue is actually caused by an inadequate diet, in view of the gut problems that you have?
Can be hard to get the right balance (whatever that is!) with enough fats, minerals, enzymes etc.
I've just read a book called The Diet Delusion, and that was an eye opener on the history of dietary advice. So much that we are told is just wrong, unproven or liable to lead to obesity.
Also describes how refined carbs seem to leech vitamins out of the body. The bad guys are definitely refined carbs, no doubts at all. Been known for a long time but it upsets the big companies so it gets no traction.
See if your library has it.

My ailments are mostly to do with a worn spine, so I get lots of pain in my neck, shoulders and lower back. This PC work is the worst!!! My shoulder just burns after just a few minutes of it.
I'm trying to minimise my pain meds and stay on the simple stuff, but I often need just a bit more. Usually I'll put up with it but then can't do anything as I just don't feel good.
No treatment for a worn spine, just pain meds or death!!! Trying the first one....