The speaker is caught in a frustrating contradiction. Other people accuse them of being "too closed off," as if the silence were entirely their own choice. But the speaker says that whenever they actually try to speak, those same people shut them down. The title, "open-," is cut off by a hyphen, which mirrors the idea: the word never gets to finish, just as the speaker never gets to.
The feeling here is a mix of exhaustion, hurt, and quiet irony. The speaker isn't refusing to open up; they're being denied the chance. The accusation becomes unfair, because the blame is placed on the person who is being interrupted or dismissed.
The mood is tense and a little bitter, but it's also very compact. The poem is one long sentence with no pause, which makes it feel like a complaint said in a single breath, as though the speaker knows they might be cut off before they finish.