That's one take on it, anyway. I'm getting the feeling that he's not really listening to you.
That's a very good point. Kind of depressing, but realistic. You tried to put off a visit, and his response was to come anyways, ignoring all your requests. You tried to dump him, and his response was to say that he didn't want to break up, then refused to leave and insisted on having the weekend as planned, and to promised to change.
Given that you were originally planning to break up with him in large part because of his habit of reacting to things based solely on his point of view, and refusing to listen/consider yours, and that the result of you trying to cancel a get-together and break up with him was him getting everything he wanted and you getting nothing, I wouldn't have high hopes for anything changing, except for the fact that he now knows that he can manipulate beautifully.
From an etiquette point of view - if, after consideration on you own, you decide "what the $#@$# just happened" and want to go ahead with the breakup, I would say that given the situation it's perfectly acceptable to *email* him, say that you've thought things over without him standing there arguing, and you've decided that you are breaking up now - he can get counselling if he wants, but the relationship
is over. You can even block email responses if you want to, or hang up if he calls.
Once someone has demonstrated that they are willing to railroad/manipulate their partner into staying with them, and won't listen to or comply with requests like "don't visit me", they drop out of the "should break up in person" category of consideration, and breaking up with them remotely and cutting off contact abruptly becomes an acceptably polite option, when it wasn't in the first place.