I'm not sure about the cPanel login site, but on the
www.x10hosting.com website, there is a 'forgot password' link underneath the 'login to account' button.
As for the 500 errors, chances are they are either due to the current server upgrades or just random downtime on the server. A 500 error is a general error code that means something on the server didn't quite work. What that means for you is that the error is server-side, not client-side.
Official support probably hasn't done anything yet because they're backlogged with support tickets from the server move. My ticket has been waiting almost a week, and I've read posts from people that have been waiting three weeks or more. Unfortunately, the admins can only do so much at a time (darn them being only human... darn them...) Patience is the key here.
My advice is to be patient and eventually the admins will be able to look into your ticket for you and hopefully gets these errors resolved. In the meantime, click that forgot password link and at least be able to access your account again.
