Adding anxiety to depression is a bit like adding cocaine to alcohol. It presses fast-forward on the whole experience.
You don’t have a second. You don’t have a single waking second outside of the fear. You crave a moment, a single second of not being terrified, but the moment never comes. The illness that you have isn’t the illness of a single body part, something you can think outside of. If you have a bad back you can say, ‘my back is killing me’, and there will be a kind of separation between the pain and the self. The pain is something other. It attacks and annoys and even eats away at the self but it is still not the self.
But with depression and anxiety the pain isn’t something you think about because it is thought. You are not your back but you are your thoughts. If your back hurts it might hurt more by sitting down. If your mind hurts it hurts by thinking. And there is no real easy equivalent of standing back up.