I feel the first two belong somewhere else, almost, because there's some light flavor of amusement when I read them.
In contrast, the last stanza was my favorite.
It was serious, lingering, and struck a chord I didn't expect to be struck.
I loved the poem as a whole, but being who I am, I'd save the first two stanzas to something else and keep the final one.
It's almost like you had this phenomenal idea to write a poem using similes about drug use and how it affects relationships, but then the first part of it was more like the parody, because you felt like you'd already written it and was having fun.
Don't get me wrong - the first two are necessary for the striking image in the third, but there's definitely a change of tone that I absolutely adore.