Man, everytime I think about my father in law, I want to punch something, so I kind of know what you're feeling. I've found exercise, particularly a punching bag when I can find one, to be very helpful in alleviating rage. As far as your attitude towards them, you need to ask them all over to sit down for a heart to heart. Tell them that you don't want to make the end of life of their mother(or whatever relation she is to them) any worse of a situation, and you'd like to clear the air and bury the hatchet. Apologize and ask them for forgiveness, and you may just find they'll do the same for you.