After all these years of being understanding, supportive, and the anchor, for not only your kids but apparently some others in your family, I think you have every right to expect them to reciprocate while you're going through all this particularly stressful shit.
You say #2 went out of his way to make you feel bad but I wonder if that's true. If you're right saying that he feels you offended him unjustly, I can understand him avoiding interaction, but couldn't that be to spare his own feelings rather than to deliberately hurt yours? Just throwing that out there, you certainly know him best, but your description of past behavior sounds like he's pretty self centered in his thinking.
Setting boundaries is probably a good idea, especially if he's picked up being manipulative from watching it work for another family member. Besides, you've tried most everything else, and you don't need the bullshit.
Aw, don't mind me, just thinking out loud. Whatever happens we still care and we'll be cheering for ya.
