Sam M's poem is about being left by someone and trying to hold on to hope while the pain is still fresh. Every line pair starts with the same words, "You left me," and then the speaker answers with something different. The repetition makes it feel like a thought that keeps circling back, impossible to shake.
The poem moves in two halves. At first the speaker uses "but" to push back against the loss: the skies are still blue, there will be a tomorrow, and the person will return. These read like things the speaker is telling themselves to stay steady. Then "but" turns into "and," and the mood softens into honesty. Today is hard, tomorrow might be better, and finally nothing matters without the other person. That last line drops the brave front. The mood is quiet and sad, with hope that seems real but fragile, and the ending suggests the grief is stronger than the comfort the speaker tried to build.