I get the sense this may have been based on experience, but either way it captures the essence of romantic passion and heartache al in one well written love poem

The persona has quite a unique voice in here. I enjoyed her sharpness, especially evident with some of the bracketed phrases (not in that order), (an indulgence, followed by allergic reaction), (read: us). She has some backbone but also seems taunted by bittersweetness and hate. The whole poem reminds me very much of moodswings, the change in emotion is apparent and erratic, very gripping, to say the least. I enjoyed how your structure is irregular yet you still managed to keep the flow steady.

I especially enjoyed this part:
"(especially on the coast
where I catch sand between my toes
and think: you would have loved it here)"
^ There's such sudden, soft sadness in here. The volume of the speaker seems to be tuned down, I could imagine it being a whisper and the persona slowly letting her eyelids sink for a second (if this were a movie and the camera was zoomed-in). This part pretty much proves how good you are at the variation of tone. Its presence is obvious, but how it came to a certain volume is played out smoothly.

Same goes for the third stanza, which, with its build-up tension, still echoes in my head.

Though I think the first line should be: "I'd just become accustom[ed]".

This is a very honest and gripping write, full of punchlines. I guess if it was a painting I could imagine the painter smashing pain onto her canvas. Yet, the outcome is wonderful. Too bad it's categorized as "explicit", otherwise I would've nominated it. Well done and keep writing.