Write for your reader, not yourself.
Use pronouns when you can.
State your major point(s) first before going into details.
I would say either a free verse poem or a short story.
Free verse- You are not constrained to a meter and it doesn't have to rhyme. You can get your point across without limiting your thoughts!
Short Story- Your example can be taught in a fictional genre, a non-fictional genre and it can be as long as you want it to be!
Hope this helps!
