The guy who parked in the space beside the one you wanted (or maybe it was the space you actually wanted to back into; I was unclear) did nothing wrong. I'm sure he had no friggin' idea what you were doing, since you stopped and I'm pretty sure he pulled into the space before your backup lights came on, being right behind you. Getting angry at him for not reading your damn mind was stupid as hell, especially since your complicated maneuver would have taken a fair amount of time and blocked access to three pretty good spaces rather than just the one you would have eventually ended up in (badly, if your parking job in the space you did end up in was any indication) while the other patrons waited for you to get your land yacht berthed--not to mention anyone waiting to pull out whom you were blocking.
Save your anger and indignation for yourself and understand that, even as humongous as your truck is, it does not have its own gravity well, the world does not revolve around it or you, and you should start parking like a considerate human being rather than an entitled ass.
Those of us who witnessed your unwarranted anger and shook our heads