Yeah, I know this well - one moment you have no thoughts, and one moment that inner world starts to awake to keep your feet standing.
How I feel about mainstream songs - are mostly about words which feel distant to a depressed person, such as "love", "life", "good", etc, and they're intensity is all "happy happy happy, be happy, WOO!" , and deep down I already know it's non-sense singing.
Instrumentals are the silence of the voices of people and the rise of abstract sounds which don't remind of happy people, so it's more pleasant to listen to.