No one can make you feel sad or angry, we choose how we react, even though its seems automatic, we have learned our reactions to certain people, events and other peoples moods.
Its pretty easy to stop this, take a breath before you snap back, become sad or feel guilty, is this the right way to react? Is this the way you want to feel? Then think how do I want to feel about this, then let the feelings flow out. Once you practice this you will have power over your feelings not someone else.