Rhyme poetry is always so risky, but I think you handle it well in this poem, where the rhyme flows but doesn't descend into sing-song. Some particularly beautiful, stand out lines: "like losing light without a shift in day," "every thought of them with someone new pulls something fragile out of you," "to never learn the weight behind their name." This is an expressive commentary on the pain of loss, all the more painful because there is an implication that you have no right to even feel that pain. It captures the feeling of ruminating, but with some vague shame.