A formal term for overcoming something, or getting over something
The term you are looking for is probably dissociation. 

There is a range or continuum of experiences that can be subsumed under "dissociation", going from mild to pathological. On the pathological end of the continuum, for example, there is dissociative identity disorder. 

Dissociation is technically a kind of defence mechanism. See for example the article Dissociation Isn't a Life Skill on Psychology Today. The International Society for the Study of Trauma and Dissociation has a long list of Dissociation FAQs.