I know you have serious problems with fats as a whole but coconut oil is processed very differently by the body, it is absorbed in the small intestine and is not meant to require bile and very little metabolism by the liver except conversion straight to energy.
It might be worth trying a very small amount and gradually increase if you tolerate it okay.
Chances are you have severely increased intestinal permeability issues (Leaky Gut) and your immune system is reacting to what is being absorbed. A test for that might be worth considering if you haven't already had it.
Take a look at iridology because it can reveal what is happening within the body and many tests can show nothing whereas Iridology can show the root causes of disease.
I have radii solaris at the top of both irises with 3 in my right iris which are very wide and can be seen with the naked eye. These mean severe hyper permeability issues of my transverse colon and stomach. My skin itches intensely as soon as I eat or drink anything! Later followed by extreme fatigue. Tests at the hospital showed that I was allergic to every food that I had been eating.
By paying attention to the itching I found a way of eating which means I don't itch, don't get headaches, don't get fatigue at least much closer to normal energy, my arms and legs don't feel heavy and drained of energy, skin problems including very dry skin is much better. I feel much closer to normal, so much so that doctors won't provide any diagnosis except for tiredness due to low blood sugars which is total rubbish because I was tired but functional and tested for low red cell count many years before the low blood sugars(BS). Tiredness and exhaustion when my BS is in the normal range but only when I don't eat in the way that benefits me.
I have tried a garlic enema and had discomfort in the right transverse colon where the radii solaris are present in my iris. The best part about it is that I know I can access the transverse colon very easily by using enemas and a little agility to keep fluid in my transverse colon. Take the fight to the cause rather than going all the way through my digestive system.
I had low adrenal function many years ago but not total adrenal failure. My iris showed that both of my adrenal glands were deficient but I did manage to restore them to close to normal function and better energy levels. I used Aloe Vera juice, I would say that it was a low priced and highly processed with thickening agents but that stuff was excellent, far better than anything else I have ever tried. Unfortunately it became unavailable so it's back to Forever FLP and the occasional other brands none of which work as well as 3 tblsp of the other Aloe I was taking. Not even a pint of juice works as well as 3 tblsp.
I hope that I have provided something that proves useful to you and enables you to find a way to much better health.