Shaming and criticizing ourselves often comes from fear. When we did not feel loved or accepted as a child we learned to protect ourselves with the inner critic which becomes an inner protector in different ways. The best way to ‘unblend’ from these protector parts is to show them curiosity stepping back into a loving protective adult that is healthier for us, becoming a force to help the True Self be more available, then asking them why they feel the need to protect us from hidden wounded parts and learning to nurture these parts. I find the following video on Inner Family Systems therapy (IFS) very helpful.
Emerging From The Dark Night 