Internal Family Systems therapy is a form of therapy that uses the idea of different "parts" of ourselves, and postulates that we can heal these different parts of ourselves by accessing an inner source of compassion underneath all these "parts" - suppressed emotional pain, defense mechanisms, coping mechanisms, etc. I've found it to be the most effective form of therapy for healing anxiety, depression, and childhood trauma, when combined with other mind-body practices.

There's a lot of videos with Richard Schwartz on Youtube explaining IFS: https://www.youtube.com/watch?v=DdZZ7sTX840

There's also a book called "Self-Therapy" by Jay Earley that gives an approach for doing IFS on your own.

Derek Scott has a great channel called IFSCA where he explains different IFS concepts - https://www.youtube.com/@IFSCA