It doesn't sound like a fat intolerance to me. It sounds like you might have a problem with your gallbladder. I would recommend you get testing for this.
I have steadily reallised the common factor in what i eat witht he daily reactions that i have and the only common thing is fat of one souce or another. some fats like palm oil which is in a gret deal of foods makes me really ill. from that i then went to monitor any other fat in my food. I have other symptoms bloating, cramp and various others. the fatigue does cause difficulty when I have had any fats. i also have to take antihistamines daily for the rash but no one can tell me why. My GP thought i was difficult case but could offer no help.
Welcome to the gastroenterology community! Have you had any testing for this? Why do you think this is a fat intolerance? Do you have other symptoms?