This is not social media and this is not Discussions; it is Forum. @mentions won't do anything here.
The moderators here can't do anything about your account. You would need to contact Fandom staff.
You need to use Special:CloseMyAccount. If you login again within the 30-day cancellation period, the closure will be canceled. So submit the form, logout, and don't log back in.
Why are you closing your account? If you just want to change your username, you can use Special:UserRenameTool instead of closing your account.