You do have a lot of courage to be facing this with an open mind. My advice would be to base a decision on authorizing a respirator on the level of your pain.
Is it going to be agony for you to prolong your life? Do you want to or need to live for your family as long as you can or do you just want to stop struggling and close your eyes to enter a new life?
Christopher Reeve (superman) was a superman and a man of courage and inner strength.
You are in the arms of the angels, God Bless You.
From My Heart,