Three short lines capture a familiar kind of mental spiral. The speaker has caught themselves overthinking once more, and that "again" matters: this isn't a new problem but a loop they keep landing in. The tone is tired rather than dramatic. There's no panic here, just a flat acknowledgment of where they are.
The most telling moment is the middle line, "no one cares to stop me." It can be read two ways. Maybe the people around the speaker really don't notice or don't bother. Or maybe the speaker simply feels that way, which is its own kind of loneliness. Either way, the sense of being unseen is clear.
The image of falling "back into the deep end" turns overthinking into water: something you can sink into, and somewhere you've been before. The word "back" suggests a return, not a first plunge. The mood is quiet, resigned, and a little sad, like watching yourself slip and not expecting a hand to reach out.