Thanks for reaching out, just to confirm, have you tried signing in following the steps outlined here: https://yt.be/help/2MGr ? Note that you must regain access to your account to delete your channel/video. Hope this helps!
These steps may help you regain access to your account: https://yt.be/help/nr5L . You can select forgot email to get other options for account recovery. If you’re still having trouble, these tips may help you through the process: https://yt.be/help/KyrL Hope this helps!