The speaker is someone everyone relies on. They are the shoulder to lean on, the hero, the soldier, the person who steps up whenever anyone else is struggling. The poem opens by listing these roles, and the short lines make them feel like a job description the speaker never really applied for.
Then the poem turns on a single question: "But who's there to save me?" The speaker has given so much to others that nobody seems to have noticed they need help too. The final line, "After i saved all of them," carries a quiet sting. It sounds tired and a little hurt, as if the speaker is looking back at all that effort and finding nothing returned.
The mood is lonely and weary rather than angry. The title, "Just a girl," suggests the speaker feels people forget she is simply a person with limits. The lack of polish, like the lowercase "i," makes it feel like a private thought written down honestly.