You can edit or delete your comments and replies directly on YouTube. If you delete comments, it may take a few hours before they’re fully removed: https://myactivity.google.com/page?hl=en&page=youtube_comments
This is the history of you YouTube comments and you can directly jump to it from this central place.
I should clarify, this is an official page from Google (as seen in the domain link). This is for people with a YouTube account, commenting under videos in YouTube. I’m simply pointing to this place, because many don’t know about it. Hopefully this post belongs to this community.