I get this. It sounds superficially like you're doing something wrong, but if you "cut someone off" by just not inviting them to stuff and then they either don't notice or don't make any attempt to reconnect with you, it means you were doing 100% of the work in the relationship. You've been putting in effort to drag them along to events they don't show any indication of enjoying, when they won't reciprocate in any way or ever make the first move, and that can be emotionally draining.

I'm not particularly extroverted and being organised doesn't come naturally to me either, so this type of thing is even more of a nuisance. I'm putting in effort to set up fun things to do using calendars and spreadsheets and research, I'm making notes about interests and mutual friends, and the other person can't even set up a two month calendar event then write "Hey, let's get coffee"?