It already happened that I initially wanted to edit a post, posted my edit and noticed that it wasn't really useful after having posted. Is it possible to retract my edit somehow?
This is currently not possible.
Take care in editing and make sure your edits are valuable, additionally considering the time it takes for two community members to review the edit.
Once the edit is handled, higher reputation users can roll back an edit as can the post owner. If there's significant harm - you should flag the post and explain why / what you feel is the issue so a moderator can assist. Flagging works for suggested edits and completed edits, but again - consider your impact on others when flagging and editing.