I know this very feeling all to well. I see things in black and white. My therapist steered me to try to be "no judgmental", not only with the person but not judging the feeling. Be aware of it, recognize and slide. One thing that has helped me is "create doubt". In other words, when I feel like someone is treating me badly or I internalize things, when we think black and white it becomes fact. I say to myself, well maybe it isnt bad. Maybe its not me. That helps me stay somewhat centered.