Under normal circumstances, you can just login to the control panel while the account is suspended.
Under normal circumstances, you should also never see the bad username/password when you’re coming from the client area, because the client area should have the right username and password for you to login. This is usually caused by resetting the hosting account password through the control panel, which you should never do.
Under normal circumstances, you can just fix the password by changing it through the client area. But that’s only possible if the account is active.
You got unlucky that the password got out of sync and that your account was suspended before this could be fixed. That sucks. But all you can do is wait for your account to be reactivated and then reset the password.
And know that there is very little to see or do in the control panel of a suspended account. You can see graphs of your resource usage, and that’s it. If you want to access your websites, files, databases, domains and any other account setting or content, you need to wait for reactivation anyways.