The speaker is writing to a long-time partner, and the poem begins as a quiet love song to life itself. Life is "great" and "sweet," so full of reasons to linger that the speaker would break Faust's bargain with the devil, the deal that trades a soul for a perfect moment, "every moment I'm awake." Nothing here is rushed; the speaker wants more time.
Then the poem turns to a private hurt. The partner never said "I love you" back, only "yes," "I know," or nothing, and the speaker coped by turning the sting into poems. But the speaker lists what counts as evidence instead: pain in the partner's eyes at causing hurt, a hand searching for a hand, three sons, one bed, sandwiches. These ordinary details carry the weight words didn't.
The mood is tender, gently wistful and settled. If the speaker dies first, it will be a wish granted, because the life shared was good. The repeated closing lines feel like a reassurance.