Hi there,
Unfortunately, we don't have the tools to directly help you with recovering accounts outside of the forums.
The best place to start would be at Youtube's Help Center, they have a dedicated page here:
https/www.youtube.com/account_recovery
Since Youtube is owned by Google, and if you've connected your Youtube account with your Google account, you can also try recovering your account from here:
https/accounts.google.com/signin/usernamerecovery
In the meantime, make sure to change any and all passwords and emails you've used recently to any and all accounts. If you bank online, make sure to contact your appropriate representative and either lock the accounts or add alerts to them.