Describe how Gregor’s insect-like body changes from the opening of the story to the ending. How do these physical changes reflect Gregor’s evolving emotional state in The Metamorphosis?

As we all know, Gregor Samsa fully turned into a giant, "monstrous vermin." This is, essentially, the biggest physical transformation that he goes through in the book. Interestingly enough, however, he doesn't seem to be particularly shocked or surprised about his newly acquired body form, nor does he wish to know why the change happened; in fact, he immediately tries to adapt to his new lifestyle as an insect and doesn't try too desperately find a way to transform back into a human. He soon realizes that some tasks are harder to do—like sleeping, for instance—but he also learns that he very much enjoys climbing and crawling on the walls.
The minor physical changes he goes through after his transformation, such as the brown liquid that comes out of his mouth whenever he hurts himself or the changes in his physical appearance, are usually metaphorical and symbolic. Thus, it's safe to say that his confusing physical transformation and metamorphosis does affect some aspects of Gregor's life, but his personality and his emotional state remain constant throughout the book; he never truly loses his humanity, and he still does everything out of love for his family. Unfortunately, his family is disgusted and repulsed by him, and they are embarrassed of his existence. Samsa fails to understand that he only lived to work and provide for his family and realizes that the only way to please his family is to die. Thus, he stops eating and eventually dies, unceremoniously and alone, similarly to how he lived.