I take it you're on mobile? In that case I'm afraid I can't help you, because I'm only on PC.

I don't know whether it's possible to bulk-block communities, but if you click on an individual community, there's a box on the right with the name of the community, Create a post and finally Block community. I've just clicked on the latter and it seems to work.

I'm feeling so very called out by pretty much that entire pic.