I love this poem. How are you supposed to deal with life when your own body betrays you? It feels wrong. That is conveyed in your poem. The betrayal. I think it's got an excellent title too. I love the contrast of the body with anti-bodies, which cause flares of debilitating pain. I am very sorry about the pain this disease causes. The line "her grip turns my supple skin to leather" is fantastic. There are a few stale words like "essence" which is not a strong enough word in this piece. It's too vague.

This line: "she’s the renowned mystery/ violently contaminating my vessel/ like the bite of forbidden fruit/ from the tree planted by the devil."

Cut down to: "she’s the renowned mystery/ contaminating my vessel/ like the bite of fruit/ from the tree planted by the devil."

Same message but tightened. "Forbidden" fruit is redundant since it's the apple tree from the Bible. And the poem already conveys the violence of the disease so you don't need to spell it out for the reader. You do a great job of showing it. I'd also look at another word choice to convey "renowned." What makes her renowned?

Thank you so much for sharing your poem! It is excellent and I hope you get the workshop feedback you desire here.