a dangerous hallucination

Alright.

Let's start with random alliterations. The main issue I have is that they mess with the initial flow of the poem. One appears in the third stanza, almost cautiously. That one worked really well. The others in the fourth stanza are the issue. They seem forced, and break up the flow. They come all the sudden in the middle of the poem and then leave just as quickly. That would be ok if the hallucination was coming and going or there were more in the poem itself. That being said, I liked them and think the poem could gain much more from their use. Looking at the third stanza alone, I feel you have a fantastic grasp on giving the devise its space while allowing it to fit. It's something that if you can make them flow, you'll be golden.

I do not like the ellipses(...). I can see how they could add to the surreal quality of the situation, but the frequency in such a short poem detract from their impact. A comma would make the second stanza flow much better. The three dots seem like too long of a pause. I like their use in the fifth stanza. You created a great sense of terrifying confusion. I did not like them in the last stanza.

The last stanza is a whole other story. My issue is that the problem(hallucinating) is not dissipated or even mentioned again. Your description of the hallucination and what should be there were very strong, and the last stanza completely drops the imagery and comparisons. I think it is too short for all the work you put into the hallucination. The juxtaposition between hallucination and real life is lost there when there could be a great gain.

Some of the shock is lost without the explanation that this actually happened. I think you could easily gain it back by strengthening the last stanza.

I have minor issues with your choice to use the word "tempest" in sixth stanza, but I do not have any suggestions as to what could replace it.

Now things that I adored!

Mentioning that the window was facing east while the sun was setting was a fantastic detail to include. The effect wouldn't have been as good without it(I tried reading it without it and it just wasn't the same).

The slight hints at the main character being diabetic where phenomenal as well. They allow the reader to feel the character's plight so to speak.

Your imagery is fan-freaking-tastic. That's the only reason I was so hard on you before. You have a special quirk about you that makes me think you could be even more descriptive. Don't confine yourself. Let those butterflies be even more fantastic, even more alive. I know you can.

I loved the stressed words being in italics. You have a great eye for making us have the main characters thoughts(at least in this poem. I haven't read any of your others...yet).

So overall this poem is only the tip of your artistic iceberg. I think it's good, but you can do so much better. Everything about this poem suggests you have a wonderful eye for the world around you and can make a fanciful story out of real life(even if said story is slightly sad and scary). You got this, so go for it.