To address your point of

On changing your sense of identity into "I don't like sugar": I do that with other stuff, and it is very effective. I don't want it to fail with sugar and therefore cause me to trust my overall identity less, so I'm not trying it with something with such high likelihood of failure, but others who like sugar less should try.

I totally see how you don't want it to become a negative spiral. For the sake of completeness, a thinking pattern that helps me in such cases is to "try on" an identity for 2 weeks or so. This feels very non-committal, so if it fails, there is less of "I'm bad at this method/my other identities must be unstable as well" but rather "well, this identity needs tweaking at the very least, but my method is still fine" sort of feeling.

What you did with summarizing the suggestions is really cool by the way. It's not a lot of added effort for you since you make a summary for yourself anyway, and I really appreciated a short summary of all the comments.