And even if you move past the paralysis, trying to cure oneself of depression is like trying to debug the operating system of your mind using a debugger running the exact same flawed logic that you're trying to debug!

Worse, those bugs are live and their nature is to slowly but surely corrupt the rest of the system software pertaining to beliefs, memory, perception and thought processing. Eventually you reach a point where it's almost impossible to tell what's a lie and what's real, or how to non-dysfunctionally process what you do discover!

This is why therapy is so critical - you have an objective third party to help debug things, identify your blindspots and point out where the bugs in your beliefs and thought processes are. A reference manual for identifying and repairing dysfunctional thinking is also incredibly valuable and to that end I recommend David Burns' "Feeling Good" to anybody in this situation.

It does feel to me to be one of the cognitive routes into a depressive state. A cluster of problems can overwhelm thinking and mood to such a deep level that it descends beyond reasoning. It's "analysis paralysis" that has worked its way deep into less rational parts of the brain to become a standard mode. Once your brain loses its sense of agency it just kind of collapses in on itself, stewing in an abstract gloop of impossibilities.