If I knew of anyone living in the conditions your father was living in - feces on the floor - I would call for a wellness check or make a report to Adult Protection Services . . . whether that individual wanted me to or not. Not to do so would be irresponsible and could set the stage for a tragic mishap.

If your dad truly does not want you to visit him in the assisted living facility, then you'll have to respect that and abide by his decision. It's a sad state of affairs, but his having that attitude does not necessarily reflect poorly on you. This family is very screwed up in ways that you did not cause. Losing contact with any of them - or all of them - might actually bring more peace into your life. Sometimes, if you hang back and leave them alone, so the "ball is in their court," they might someday initiate contact with you. Try hanging back for a good little while.