That sounds like tough stuff to deal with. i have never had to contend with that kind of family stuff. The only thing I can offer that might be helpful to you is my experience of "talking through" to younger ones (thinking about your Kevin and Kitty) to let them know they are not alone and never need be alone again because you can be there for them. It really helps our younger parts when they know we more capable ones have their backs. Maybe talking through to them and letting them know you will always take care of them and be there for them will help them not fret so much about you all leaving home.
Take care.