At first I found it really hard to not eat wheat and other grains, but now after
forty years there are a lot more gluten free products in the local supermarket
If I have a reaction it is usually from processed food with preservatives, eg
ham, I am also allergic to citrus, and some other fruits and nuts.

Your allergies are similar to mine. Do you go to restaurants/pubs and watch others eat. The thought of not eating out again is depressing.
Looking forward to much missed holidays but a big part used to be eating out