Oh no! Are you still able to sign into YouTube? If yes, we suggest adding extra layers of security to your account with these tips: https://goo.gl/8ahrLA . Also, you can try changing the email address of the channel, here's how: https://goo.gl/ETpfS7 . Hope that helps.
Ok so I just made a new email set up a page with a brand account invited my old page as the owner so I can then just give the YouTube account to the new email but where do I verify the invit for the old account