Dr. Pat Love wrote a book about this phenomenon called The Emotional Incest Syndrome: What To Do When A Parent’s Love Rules Your Life. She describes the cost to the child, “If the parent represses the girl’s (or boy’s) anger not just once but over and over again, a deeper injury occurs: the girl will eventually dismantle her anger response. Ultimately, it’s safer for her to cut off a part of her being than to battle the person on whom her life depends.”
There’s the setup for perfectionism and depression. You begin to feel that your life should be devoted to the well-being of that parent. And you better be really good at it—or something bad could happen.
Dr. Love’s point? In order to emotionally survive, you cut off the anger as you feel more and more pressured to meet the expectations of the parent on whom you depend—at least as a child. And even shame yourself for any feelings of resentment that might try to seep into your awareness.