Just go to Cpanel and phpmyadmin to unban yourself. For table adopts_users, change the usergroup to 1 for your admin user, and you will be able to access ACP again. Also go to table adopts_users_permissions(or adopts_users_status if using version 1.3.5 or earlier) and change the permissions to ‘yes’.
I am curious what you did to get yourself banned on your own site. I think mys v1.3.6 added a check that autoban will not work for admin users, but on mys 1.3.5 or earlier you can still accidentally have yourself banned even as admin.