In The Metamorphosis, Gregor is unable to find his own identity due to the lack of compassion and recognition from his parents, as well as the dislike of his job and the path his future is heading in. With this constant unrest from his lack of purpose, Gregor mentally (or physically, depending on your view of the story) transforms himself into a whole new creature. Gregor attempts to form and shape his identity by changing his entire physical self. As Gregor changes he realizes how much more of an outcast he becomes by becoming a bug, because he has now disgusted his family and made them despise the thought of a beetle within their house.
Gregor tries to create a new identity because he hates who he is becoming, however when he changes, he is hated even more than before and becomes completely useless to his family. Tragically, Gregor's attempt to create his own identity makes him an outcast within society as well as his family.