Depression can be a vicious cycle; when you are used to feel depressed, joy can feel like a threat because at the opposite of it there’s sadness.
Depression and sadness are different!

More often than not depression feels like nothing, so one may think “I would rather feel nothing to feel joy and in some point feel sadness”.

But let’s face it, you ought to feel to not feel. Depression is not good for you, it may look liked you encounter with it often, but it isn’t. I can’t stress enough over this, it isn’t !!
Face it, and take yourself out of this place!