Question

"If you see me getting smaller, I'm leaving, don't be grieving, just gotta get away from here. If you see me getting smaller, don't worry, and no hurry, I've got the right to disappear."

Answer 1

Emotions

your hopes get smaller as you get sadder, your happiness leaves, you dont want others to feel bad or grieve because of it, gotta get away from the thing that is making you sad.

Suicidal

If you see me getting sadder, dont worry, dont hurry to help it wont do much, ive got the right to get away from this place that is hurt me.

thats what i think it means, sorry its depressing