Hey, I'm a therapist and I know about introjects and would work with someone on learning to challenge the negative content. My T also knows about introjects and would do the same. As wpowers said, the first step is to learn to recognize the introject when it appears.
Yes, it is a coping mechanism that is less helpful once you are out of the situation that necessitated it. It had a purpose and was born of self-preservation. It is understandable, even if painful now.
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“We should always pray for help, but we should always listen for inspiration and impression to proceed in ways different from those we may have thought of.”
– John H. Groberg