Hello, I've just come across this and it totally resonates with me. I used to enjoy cooking, giving dinner parties, going to retaurants, etc. but since my diagnosis in 2018 eating has become at best a chore and at worst an endurance test. After three years I've just resigned myself to the fact that I'm never going to enjoy eating again. I like fruit (but we're only allowed three small portions a day) and I like most vegetables but I don't get any enjoyment from them. I've got to the point where I'm frightened to put anything in my mouth as I don't know what it's doing to me. I started having therapy but had to stop at the first lockdown. Currently trying to get my weight UP to 7 stone! Like you, I only really enjoy carbs and I do allow myself two sandwiches a week and a boiled egg with toast once a week; not on the same day. I know what you mean about dieticians! The therapist said I needed to be kinder to myself and have a treat occasionally so sent me to a nutritionist to reassure me that that would be possible. However, after three months and several hundred pounds! she only told me what i knew already - carbs spike your blood glucose levels - and removed cereals, oatmeal and bread from my diet!
The only thing I have done that helps a bit is to make 'cakes' with ground almonds instead of flour and erythritol instead of sugar. There are lots of recipes online but, be warned: none of them are what they say they are. 'Shortbread' certainly isn't, keto 'bread' is nothing like bread, 'muffins' aren't. You just have to work round the disappointment.
I hope you've found something useful by now.