I call them demons because they may as well be. They are the voices in your head that seek to undermine all your attempts to feel joy, hope, self-forgiveness, truth, etc. They're the "I'm not enough" or "I don't have what it takes", or even, "I'll just have that talk with so and so next week".
I suggest that they work to ensure you never get something started (inertia); and if you already have something started, they work to ensure that you never finish it (entropy).
The demons are spawns of fear. Fear is the catalyst of doubt, worry, anxiety, and stress. There is the intrinsic "healthy" fear that tells your body to run from the lion -- and you should. But that dance you have to choreograph, that paper you have to finish, that (again) difficult talk you need to have with your friend or spouse is not a meat-eating predator. And yet we treat the most important things we need to face as if they have sharp teeth. And not facing them only makes it worse, for you either pay now or you pay more later. Paying later sucks more for all parties involved.
The demons like to keep you in a complacent limbo, and if they're really successful they'll have you forget or lose sight of what you set out to 'initially' start or 'eventually' finish. They'll employ distractions. This comes in the form of people, entertainment, or go-to coping mechanisms (pint of Ben and Jerry's, pints of beer, or a pint of self-deprecation).
Neurologists (each in their own way) will tell you that your brain has a lazy disposition, and if it's not challenged, it will move into states of rigidity. Hence the expression "Can't teach a old dog new tricks" -- it's not that the dog isn't willing, it's just that the dog neurologically can't. Okay, point being..?
Point being is this: I suggest that you have a certain set of agreements, whether you're aware of them or not, that keep you from starting or finishing something. And the good news is that these agreements can be changed! NEUROLOGICALLY! How? The same way you'd attempt to learn a new language: time and repetition. I don't know WHAT agreements you have that keep from openly feeling joy, hope, love, peace, or contentment. That's something each of us have to work out with fear. I know. You have to partner and collaborate with fear to overcome it. It brings light to the expression, "Know your enemy," I suppose.
To beat the demon, face the demon.