Sarah's poem is about the emptiness that follows when someone you love walks away. The speaker begins by crediting this person with saving their life, and the proof is in small, tender things: fingertips brushing a cheek, being held. These details feel gentle and vivid, as if the speaker has replayed them many times.
Then the poem turns. The line "but you left" arrives bluntly, and the last two lines, "and i haven't felt a thing / since," are the heart of it. The person who made the speaker feel alive has also taken that feeling away. Notice that the sentence "you made me feel" is left unfinished, with no emotion named, which suggests the feeling was too big for a single word.
The mood is quiet, sad, and a little hollow. The short lines and lack of punctuation make it sound like someone speaking softly, without energy, still stuck in the loss.