I just linked my youtube account "rebel******" to my gmail account "rebel******@gmail.com". When i sign back in i get this message:

You have linked your YouTube account (__sEAoa4mN2U__) to your Google Account (rebel******@gmail.com).

Note: Your old YouTube password will no longer work. You need to use your Google Account password from now on.
If you made a mistake, you can re-link __sEAoa4mN2U__ to a different (or a brand new) Google Account here.

This is not my account. I never seen or created that account. Now I don't have access to my old account.