Sam M's "Change" is about someone who reshaped themselves for a partner and got nothing back. The speaker changed their clothes and even their personality, but the other person never noticed. That silence is what finally makes the speaker ask why they should stay "this person" and say they want themselves back.
The feelings are tangled. The speaker says this person makes them happy, yet also feels like too much for them, a "stress." When the partner takes breaks, the speaker feels it and "gets worse." Underneath is a harsh self-image: "not pretty," not "skinny," not "close to normal," lines that sound borrowed from the partner's voice ("like you said"). The speaker hides all this, since nobody knows and they don't dare tell.
The mood is sad, raw and lonely. The short, plain lines feel like a private confession, and the ending, "you'll never know," leaves the pain unspoken.