It could be worse, but it sounds pretty bad if you can't even eat the dregs that FODMAP has left us. I've had similar problems (tho I'm lucky enough to still have my gall bladder). If your problem is certain oils, have you read any of Dr. Cate Shanahan's books or visited her website? She writes extensively on the effects of vegetable and seed oils that are in most prepared foods: what she calls "The Hateful Eight." Here's a condensed version -- https://drcate.com/the-hateful-eight-enemy-fats-that-destroy-your-health/