The speaker makes a single, careful distinction: they don't want to die or hurt themselves, but they do want to vanish for a while. The whole poem turns on that difference. It's a way of saying "I'm not in that kind of danger, but I'm not okay either," and it sounds like someone trying to be honest without alarming anyone.
What the speaker seems to feel is exhaustion and overwhelm. Disappearing here doesn't mean an ending. It means a pause, a place to step out of the world until things settle. The phrase "until I feel okay again" is quietly hopeful, because it assumes that feeling okay is possible and will come back. The comma floating before "I just want" even makes the line feel typed in a rush, like a private thought written down as it arrived.
The mood is tired, vulnerable, and plain. There's no decoration, just a small, direct confession that many readers will recognize.