What does depression feel like for you? Metaphors Welcome

I have depression / anxiety and I struggle to describe what it feels like. Paint me a picture of what depression is like for you.

Depression is a mind-marathon with no end in sight:

A bad day feels like I'm running/sprinting for miles inside my mind, knowing I'm going in circles, but unable to stop. And you don't know when it will stop. Your body aches and you're exhausted.

Happiness now feels like a game that I used to know how to play, and then I suddenly forgot.

Feels like I'm watching from the sidelines and when I get thrown in, something inside is constantly telling me that I don't belong there; that others will find out something isn't right with me.

Things that used to make me happy don't anymore. My S.O. (the only one that knows I'm struggling) presents me with these things (like a dinner out, or fave movies) and while I really really want to enjoy them, nothing stirs up inside me except the feeling that I'm letting him down.

Anyone else?