self-exile

Short definition from Wiktionary

Noun

1. 1
   A voluntary exile; One who chooses to leave their homeland or community.
2. 2
   The state of voluntary exile; The condition of choosing to leave one's homeland or community.
3. 3
   Isolation from the world; A retreat from involvement with one's environment.
4. 4
   A separation or alienation from ones inner self.

Verb

1. 1
   To go into self-exile.