Go to YouTube.com;
Click on settings far down on the left bar where your subs are;
Click on Settings;
Click on "Advanced settings"; // www.youtube.com/account_advanced
Delete Channel: Click on that blue highlighted "Delete channel";
Log in with your Password and check if it is the right g-mail adress;
Confirm;

Another way:
Go to YouTube Studios; // studio.youtube.com/channel/
Click on settings;
Click on Channel;
Scroll down to the bottom;
"Other Settings"
        |->Remove YouTube content;
Then sign in;
Confirm with your e-mail adress;