Young Writers Society

I thought it was excellent. And, xanthan gum, that's not a double negative, however much it may look like one!

I didn't believe my parents when they told me about monsters
not existing under the bed

The grammar and punctuation are fine, no comment there.

Concerning the poem itself:

"I should have known better than to go messing
with someone like you, the kind of person
who says "I love you" in the same tone
you say "I'll be there at seven-thirty"
and you're always there at eight." - the only word I could think of to describe this was generic. I've heard it before. I wasn't exactly disappointed but I felt it lacked a personal touch.

"as long as you have someone to plug
the emptiness inside of you." - that was new. However, I was left wanting to know: why? At the risk of going off on a tangent I think it would have been worth expanding this section.

"I didn't believe my parents when they told me about monsters
not existing under the bed, but now--now I know, I've found
the phantoms living in the space between the floorboards,
behind the headboard, trapped in the glass preserving photographs
and lost in picture frames." - at first this seemed separate, I couldn't link it with the rest of the poem. After a re-read I (think I) got it, maybe I'm just slow.

"And now it's late, this bed is empty,
and there is no one around who loves me
enough to tell me lies." - a great ending. You rip the line structure in two, akin to the breaking of a heart.

I enjoyed it, and although I have little experience with such emotions you still managed to make me empathise.