We'd like to help. Here's a guide that may help you regain access (it covers more scenarios): https://goo.gl/q2Ijwz . Hope the account gets recovered.
The email address on the channel can only be changed if you have access to it. You can try recovering the username/email with these steps: https://goo.gl/CBj5KC . You’ll need to know the name on the account. Here are some additional tips: https://goo.gl/QtskMp . Keep us posted.