Cannot authorize my computer

Whenever a computer dies I get a new one and am faced with losing iTunes. I cannot authorize my new computer because Apple says I have 5 others. These 5 are all dead, over a period of decades. I go to deauthorize them and Apple only will allow me to deauthorize my new computer, which I want to authorize. Nowhere does it show the old computers, none of which exist, they are all dead, dead, dead. This is the most confusing idea anyone ever had, I want to get rid of dead computers and can't. I want to authorize my new computer but it won't let me because it thinks I have five others, but they are all dead, dead, dead, dead, dead. This is insane, I am locked in a hopeless loop. Google tells me I can click on deauthorize all five old computers, but that option does not show