Fog is the first thing we meet here, and it sets the tone: nothing is clear, and nothing quite has edges. The speaker is describing dissociation, that feeling of being cut off from yourself and your surroundings. The line "You are not here and you are not real" is stark and flat, as if the mind is stating something it can't argue with.
The speaker seems to address "you," which could be another person or a split-off version of themselves. Either way, that person is "made of paper," thin, weightless and easily torn. The anxiety and despair pile up, and the only response left is to "curse and swear" that it must all be a dream. That reads less like anger and more like bargaining with reality, hoping the feeling will turn out to be false.
The mood is eerie, numb and quietly desperate. The short, plain lines and the simple rhymes ("air," "despair," "swear") give it a trapped, circling quality, like a thought that keeps repeating.