The speaker takes the blame for everything that has gone wrong in her life, and the repeated "my fault" turns into a kind of chant. The list starts with lost friendships and fighting parents, drifts into small things like ruined shoes, then drops into self-harm and a suicide attempt. Putting a ruined pair of shoes next to a suicide attempt shows how blurred her sense of responsibility has become: everything, big or small, lands on her.
The mood is raw, tired and sad. She hides her sobs, tries to hide her swollen eyes, and cries in the shower where no one can see. The short line "it's a sacrifice to the heart" stands apart, as if she is pausing to catch her breath. Near the end, a friend's remembered words suggest she keeps giving to people who hurt her. She admits "he wasn't wrong," yet she still ends by apologizing for simply being herself. It's a painful, honest poem about guilt and low self-worth.