Can't access admin dashboard.

I had an admin account then I created another admin account and changes the first admin account role to the customer. Then I restored my website from a backup that I had made just before making changes to the admin accounts. So it deleted the new admin I created and wouldn't give me access to my old admin login. I tried creating a new admin via SQL but it wouldn't go through. I tried changing the existing (old admin) privileges but it still wouldn't let me access the back end. I have my login information correct it's just that it will log in but says I cannot access the backend.