URGENT Site has been hacked and I can't log in

I really need help here. My site has been hacked, and I guess it must have happened through WordPress, not my host, because I’m now locked out of my WP access — WP doesn’t recognize my email as being connected with an account, so I’m lost even starting to deal with this.

Can someone point me in the right direction to restore access to my account and restore my website? I am not terribly savvy about these things, so I need all the help I can get! Many thanks in advance