First I would suggest 5 mins for planning. For the seen part of the section I list down the theme (what’s presented, how it’s presented etc...), structure, ideas, and language. Then I list those for the other poem. Then just compare in the essay. Eg: Keats presents poetic ambition as....in poem 1 with the use of an extended metaphor..... In poem 2 poetic ambition is presented as....
Do that for theme, structure, ideas and language and you should be fine. I would recommend structuring each paragraph like this:
-Point about a theme/structure/language/idea
-Quote
- What it means
-Alternative idea
How it links to the whole poem
-why the poet has done this
Switch between poems from paragraph to paragraph. Good luck!