Awww, so sorry to hear about your problems, elle. It sounds like a nightmare.
My friend's stepson has a rare condition in which he has to eat a highly specialized diet, which contains no protein of any kind, or something like that. I swear, I think he just eats avocados and vegetable soups mostly, and can't have any grains or meat or dairy or sugar or anything like that.
They discovered it when he was an infant, though, because he nearly died from his allergies and if he eats anything with protein he would probably end up in the hospital as his body can't digest it. I think he gets special shakes made for him as supplements and has to take a lot of medications. Oddly enough, he is very healthy and doesn't seem to mind the diet as he is so used to it. I don't have any advice to offer, but just wanted to say that there are some extreme conditions out there in which a special diet is needed, and maybe if they continue to run some tests they will discover what is causing the problem and you can learn to cope with it in order to have a more normal life. In the meantime, are there any support group for people who struggle with Crohns and other gastro stuff who maybe also feel stress and anxiety from their conditions? Perhaps you could find an online forum, even, just to speak to others who are facing the same sort of problems? This sounds so miserable for you, and seems to be affecting every aspect of your life. I think you should really stress to your GP how much this illness is affecting your life and wellbeing and let them know that you really need some help here. And in the future, I think it would be a good idea, if you can, to talk to your workplace and let them know what is happening. I had to tell my boss and several other people in my office about my breast infection, and while it was embarrassing to discuss at first, everyone was sympathetic and I was given as much time as I needed to cope with it. Everyone knows what IBS is, so maybe just tell them you have a severe case of that (until you find out what is really going on) if you start missing a lot of work again. Good luck, and I really hope you feel better soon. (((HUGS)))