Other comments here give good advice about how to deal with well-intentioned technical criticism: meditation, journalling, etc.

For dealing with snarky or nasty criticism of you or your character, I would highly recommend listening to recordings of Marshall Rosenberg's books and/or seminars on "non-violent communication" (available on Spotify, Audible, etc.) The NVC philosophy is absolutely game-changing: it's to change your focus away from the "jackal comments" and empathise with the human needs underlying them. It's God's work -- connecting and healing for you and your critic.