Check out the Anti-META Fedi Pact. There are already lots of instances on the list. Beehaw has made a post proving that they have signed it, but the site has not updated to add them to the list yet. Note that being on the list does not necessarily mean that an instance is LGBTQ+ friendly, so make sure to verify for yourself.
Something that helps me is to change the way I perceive myself in these moments of anxiety. I separate my pre-transition self from my post-transition self and think of them as distinctly different people. Any embarrassing or uncomfortable situations are just experiences of my pre-transition self that doesn’t define my post-transition self. It’s like a temporary feeling of just letting go and not caring about the consequences, because it’s a totally different person dealing with it for me.
You could also remind yourself that in the grand scheme of the universe, this moment is an insignificant speck of time.