The speaker is caught in a painful standoff with a close friend. Both are hiding something, and each keeps insisting that nothing is wrong. The speaker knows the friend is struggling, wants to help, and keeps getting pushed away with lines like "go away" and "it's private." The friend even seems to treat the speaker as a "toy," which makes the speaker feel useless.
What makes the poem sad is that the speaker is doing the same thing. They put on a smile, say they're "good or great," and hide a wall of their own secrets, even though they badly need someone to talk to. The friend they would normally turn to is the very person who is locked in silence.
The mood is lonely, tense and quietly desperate. The plain, repetitive language, especially the recurring "pretend nothing's wrong," makes the exhaustion easy to feel. The last line, "one day bye might be for good," is a worrying hint that the speaker may be in real danger.