sweet tooth

I think you could make this more powerful with more descriptive word choices.

"I can't help but think of" could be replaced with something that shows your exact emotion towards the subject in reference to them looking at a different person. I want to feel what you feel, you know? jealousy, insecurity, anger. It leaves the reader guessing what you're feeling and it just feels like reading something. make it feel like feeling something.

I was your last meal and she is your sweet, sweet dessert. She is what you began to crave once you were full of my savoury soul.

I like that line. excellent in my opinion.

I'm sorry I wasn't sweet enough to satisfy your desires.

I feel like this could be scrapped entirely and replaced. go into more detail about what you felt after this (or what you feel now). open the wound and let it bleed through your fingers, you know? I'm 110% positive that being sorry you weren't enough to satisfy their desires isn't the only emotion you felt through this (been there), so just write about it, about all of it, you know?

I'll focus just on the use of metaphor here. On the positive side, the metaphor here is clear and conveys information concisely: the subkect had a worthwhile (savoury) relationship with the narrator that he abandoned in favor of a more attractive but less healthy relationship with someone else. That's good, but metaphors are also images and the imagery is just unfortunately gross and silly: namely of someone cannibalizing sweet and savory bodies with their eyes. Unless you are writing a comedy piece (e.g. Lemon Demon's "Sweet Bod") that's really inappropriate. I think you need to be more careful of the tone of your imagery versus what time you intend.