I highly recommend using cloudflare's csam scanning tool to stop illegal images from appearing on your site. It also helps to block proxies as well. I think as an imageboard community we can stop this shit but we need to start taking measures to put an end to it. If you want to step away from your board for awhile don't leave posting open. It will get spammed. Just put it in read only until you come back.
And yes, I'm posting this on all the imageboards I find. No I'm not a bot.