If nothing else, poetry is not prose.
What does that mean? It means that the sound of poetry: both the way individual words sound (sweet, harsh, suggestive of some meaning) and the way the sound moves (the rhythm) is a key aspect of how poetry works.
If you want to explain how a poem really works, you have no choice but to deal with its sound.
The simplest way of doing this is to focus on the poem’s key moment of dissonance. Ask yourself, where does the poem’s sound pattern / rhythm break down? Where this happens (or if it does not happen, or if the rhythm intensifies, speeds up, or slows down) will usually offer us the key to understanding the whole poem.
Showing you ‘get’ a poem is difficult; asking yourself why does the poet change the rhythm just at this point, is the first step.
Here are ten lessons that explain poetic form (how poetry works)