Here is a speaker working up the courage to come out to someone, and the poem follows the nerves in real time. It begins with a "silent, chilling voice" in their ear, which the speaker admits is only an echo of their own choice. The fear, in other words, comes from inside, not from anyone else.
The second stanza is a plea for bravery, with the speaker wishing they were stronger and admitting that the wait is dragging on. Then the body takes over: a blush, rising heat, and a quick backup plan to laugh it off as a joke if things go badly. That small detail shows how scary the moment feels.
Finally the speaker gives up on planning and blurts it out. The stuttering "Uh... HEY I'M GAY!" with its spaced-out letters and abrupt dash feels awkward, loud, and unfinished. The mood is anxious and tense, but also funny and a little brave, since the speaker does it anyway.