Quick thing - you aren’t obligated to throw out Neil Gaiman books you already have, but you probably should pirate media from him in the future so that there’s no profit for him.
As far as shaving your head, it should be pretty easy to do with a decent pair of clippers, and a nice safety razor.
because my leaving will not change anything.
Well, telling him that you won’t support someone that doesn’t believe other people exist may not change his mind, but it might convince him to keep his bullshit to himself so that he doesn’t alienate people that are his source of income.
Nuke the world.
That’s not murder; it’s a war crime.