Please don't be so hard on yourself HaWho! Changing the relationship dynamic is so challenging; especially when only one person is doing the work. You'll get this.
I totally understand the difficulty with the silent treatment. It hurts so much to be ignored. For heaven's sake, you live under the same roof! For them to just turn their backs on us as if we were invisible is like a kick to the stomach. But this is THEM. Not us. Normal, civilized human beings don't treat each other this way. I get treated better by the strangers in the elevators I encounter at work everyday. Lol!
