Put question marks when you have rising intonation.
I suggest you read your poem out loud. Do this multiple times and really do it out loud, not just in your head. Try it with and without the question marks. Or try them in different places.
Punctuation is a guide for how to speak writing out loud (of course it also serves other purposes, including for silent reading). Commas are short pauses and periods longer ones, for example. Exclamation points give emphasis and question marks change intonation, something we associate with questions, even if no question is intended.
Figure out how you want your poem to sound. Read it out loud to others too, to make sure it lands the way you intend. Once you know what you're aiming for, add in punctuation to get that effect. In other words, someone who has never met you should be able to read your poem out loud and have it sound just like when you read it.
While this technique can be helpful for writers of all genres, it is especially useful for writing such as poetry which often has fragmented lines such that standard rules of punctuation don't apply in any obvious way.