What are the articulations of themes, technical devices, and structure in the poem "Malade" by David Herbet Lawrence?

The French word "malade" means sickness or malady, and the poem describes what it feels like to be sick and then uses contrast, in the final stanza, to show what it feels like to be well. The theme of the poem is the misery of illness contrasted with the joy of health.
The poet universalizes the malady: The first-person narrator doesn't tell us what illness he or she is suffering from, meaning we can apply the feelings described to any malady, be it mental or physical.
The poem relies heavily on imagery and metaphor to convey what it feels like to be ill and well. The main feeling conveyed in stanza one is emptiness, as the narrator both observes and projects his own feelings on to the objects in the room; he is sick, therefore the grapes by his bed seem to him to be "sick." Lawrence shows us rather than tells us of his narrator's boredom: we experience the sick person's bored state as he watches the breeze make the tassel of the blind tap against the windowpane, something a more active person would not be likely to notice. He feels emotionally hollow, using the metaphor of his room and hence of himself, as a gourd, "scooped out and dry." He likens himself to a spider lying on "dust," who sees nothing but "twilight and walls." These images convey to the reader the dreariness of being sick.
If the first stanza has a dry, emotionless feeling, conveying boredom and emptiness, the second rises to a crescendo of emotion. Here, the poet extends the metaphor of himself as a spider, describing the state in greater detail. He uses exclamation points twice to underscore his emotions, both of wishing to be "outside" of his room and of feeling like a spider, stuck in a cave. He ends the stanza saying he is choking on being confined to his sick room. He uses images of "creeping" and "gray," which are spider-like and dull, to convey how trapped he feels.
Finally, in stanza three, he contrasts his confined, spider-like state of illness with imagery of birds outside soaring free in the sunshine. Unlike him, the birds can fly in the "vast spread country." They symbolize good health and the expansive liberty that it offers. To the narrator, the birds are "ecstatic," (this reflects the narrator's own thoughts and desires, as we don't know if the birds are actually ecstatic). He uses the image of the birds to show how ecstatic he himself would be—as if soaring—were he healthy again. 
The poem is in three stanzas that are held together by imagery rather than rhyming words at the end of lines. In the first stanza, alliteration provides a sense of rhythm: "tassel" and "tapping," "scooped" and "spider," "watching" and "walls." In the second and third stanzas, repetition, such as of "wet," "spider" and "birds" is what adds a sense of rhythm.