You have a right to your feelings! If feeling bitter helps you, then go for it, hang on despite what anyone else says or feels. When I'm very frightened, feeling hopeless, often the only way I can get out of that "hole" is to get angry; "appropriately," inappropriately, doesn't matter. It works for me. Don't let anyone else tell you how to feel. I remember the old joke/response to "Have a good day" -- "Don't tell me what kind of day to have.!"