Someone Hacked my computer with a book, when I opened it I was banned and Minecraft crashed.

I was on my server and decided to turn off the whitelist then this player named boba_milk joined, and they started griefing the server. So, I gave them adventure mode then he started killing afk people, I stopped him and he asked for gamemode, I said "no you will use your Hotbar saves to spawn broken items and destroy the server." He said he wanted to show me something, I told him Fine. Then, he gave me a book. I opened it and instantly got banned from my server, I checked the console and he started running commands like /IP AmethystBrake22 because I had the EssentialsX plugin he thought I had the EssentialsGeoip plugin because people usually have all the essentials plugins if they have the core plugin (EssentialsX) which I didn't have the GeoIP one (thankfully). Then he ran broken commands that were too long to type in chat so he gave himself a command block then I shut down the server and booted it back up with the whitelist on. A few minutes after, my computer started acting up getting laggier and laggier. after about 20 mins of it getting laggier, my computer froze completely and after about 10 seconds of being I started hearing doot doot doot from my headphones and my heart stopped. I knew something was wrong when that happened, and as I'm typing this my antivirus is going in the background and my screen keeps moving around with my mouse staying still.(read carefully) I think this is a different version of the chat hack that was happening a while ago where people could type something in chat and get access to your computer but this is with a book and to confirm it someone was trying to get on my PC by connecting it with theirs I saw it in task manager and my antivirus suspended the program from continuing but I'm still pretty dang sure that I still have a virus because my computer is still acting up. Also my Minecraft username is AmethystBrake22 to clairify. Im reporting this bug hack thingy so it can be stopped immediatly.