OK, it has become clear to me that my account has been hacked. Although my password wasn't changed (just did that myself, and removed payment information), someone used the "deactivate all" feature on this website and activated 5 PS3s that aren't mine. Since I can't use that feature for a while now, and deactivating my own device won't open any spaces on my account with which I can play my own games, it's clear I'm going to have to create a new account..
Since my machine won't play discs anymore, I purchased a few games from the PS Store that are stored locally. I can't play these games on a deactivated console, and if I create a new account, I won't have access to them, as they were purchased under my current account. Is there a way to transfer from one account to another?