The line from The Metamorphosis shows us that although Gregor has changed into an insect, he still has human thoughts and emotions. He can still think and feel like a human and appreciate the finer things in life, such as music, which would presumably be lost to him if he were solely an animal, especially an insect. So the line shows that although he has physically changed, mentally and emotionally he’s still a human.
Gregor’s role as a son and brother also undergoes a transformation along with his physical transformation. Prior to his transformation, his entire family is dependent on him and his job. However, after his transformation, he becomes dependent on other members of his family for his sustenance and survival. For example, in the initial days after his transformation, Grete feeds him, and he comes to depend on her for nourishment.
Gregor struggles with a number of identity issues in his new form. Although he has been transformed into an insect, he still has human feelings and sensations. However, being an insect, he cannot find a suitable outlet to express his feelings and emotions. The few instances in which he tries to reach out to other people or experience pleasure, as when he wants to hear Grete play the violin, he’s vehemently dismissed because of his repulsive form.
To give your characters struggles and/or motivation, you need to find something they want to strive toward. Your character is a person, just like anyone in real life. They have goals, they have things they hate. They have a backstory that could provide a reason for their struggles, such as they grew up in a fairly wealthy home, but now they got disowned and are dealing with how to make their own money.
Motivation tends to come from a struggle. For example, the character that is struggling with how to make their own money also has a motivation: money. They are used to having money, that now that they don't, they're going to try to get that money back. Sometimes, the character will have a lull in their motivation, which gives a perfect chance for a climax in the story. Something big happens to give them their push. Maybe they lose the apartment they were staying in because they were too lazy to find a job. Or maybe their significant other tells them that because they're such a worthless, jobless loser, that they're breaking up. No matter what this big event is, it shakes the character out of whatever lull they've been having and shows them that they need to be able to overcome their struggle, therefore providing them with their motivation back tenfold.
I hope this explains this well enough for you, but I can always try to answer in more detail if you'd like.
Muir's use of diction in this paragraph, clearly shows how effective his language. The bolded words, like difficult, force, crooked, struggling, etc. create a tense, painful, and frustrating mood. Muir uses these words describe how his journey was through the wading bogs, and swamps and he uses these words to describe what he went through before finding the Calypso Borealis.
