I'm a guy who loves bicycling but do not share the view that a bicycle going twenty miles and hour belongs in the same lane as vehicles orders of magnitude larger and moving ten or more miles per hour faster. Per the posted speed limit.
If you choose to ride for any reason besides "recreation" then you need to accept you're stepping into a world where people think the roads were built for them and them only. That you're infringing upon their territory.
Sometimes those people see their vehicles as big anonymizers; giant shields which protect fragile egos. Unfortunately, on the road, we're the fragile ones and they aren't.