You're right. I was foolish. He ran me through AnyDesk and unlocks and told me to type in Terminal among other things. AnyDesk gave him remote access (which I later learned). He ran pages of code. He called me from "his private secure phone" because he said our phones had been hacked and "they" were monitoring our calls. He said he had gotten the cybersecurity team on it and they found the Trojan virus, blah, blah, blah.
Meanwhile, I got on my Ipad and did research--which I should have done when my Mac blacked out instead of calling the fake #. Both that # and his "private" # were listed in scams. I finally told him I was done and would block him and report the scam. I called Apple Support and a kind woman took mercy on me. She helped me delete AnyDesk and told me to contact Amazon and my bank to change passwords. (He had me go to those accounts to see if there were charges. ) She told me how to get rid of that black warning screen by myself if it ever came up again. And she told me to file a report a phishing scam report to the SEC.gov.
What a mess. Lesson learned.