The poem is a single plea: "Don't leave me alone with my thoughts." Nothing else is given. We don't learn who the speaker is talking to, or what the thoughts are, and that gap is part of what makes the line work. The listener could be a friend, a lover, or even no one in particular.
What comes through is fear, but a quiet, ordinary kind. The speaker isn't afraid of a monster or a stranger. They're afraid of their own head, the place most of us can't escape. Being alone is usually thought of as peaceful, yet here it sounds like a threat, as if the thoughts turn on the person who has them.
The mood is tense and vulnerable. The line is short and direct, with no decoration, so it feels like something blurted out at a hard moment. The title, "Bai," and the bracketed "[2]" hint at a larger context, but from the text alone, the main impression is a person asking for company.