I am glad you're out of danger.

Since he himself claimed to have delusional disorder (it's not always possible to identify it by yourself), and scorned you for having mental health issues; it seems he might have something other than delusional disorder (may be a narcissistic, or an antisocial) and I suggest you to possibly seek legal help (from a police officer) when he tries to harass you or abuse you.

It's not impossible that some cybercriminal is trying to have him persecuted, or trying to ruin his life, but it's unlikely unless he made someone with a degree in Computer Science Engineering mad for reasons he didn't tell you. Or he could have blacked out, or he is just gaslighting you (this makes me nervous.)

I suggest you to go to the local police department and verify his claims. If they aren't true, he will get what he deserves. I suspect you're in danger because of him.

Edit : I have a fair knowledge of computers and I advice you to follow Malwarebytes blog to make yourself familiar with cyber security (by following the news and reading good practices). Again it's not impossible someone is eavesdropping you, but I think it's highly unlikely unless he was involved in illegal activities.