You do not deserve success! No one owes you a damn thing.
You must be ruthlessly honest with yourself, and only tell the truth, even when it is hard. Especially when it becomes hard. It is only where it is hard, that the opportunity to improve and develop your self-discipline arises.
Your voice is the only unique quality to writing.
Voice: being the sentence cadence you naturally use in prose; dialogue patterns (more natural speech, Stephen King; stylized speech Joss Whedon); and your personalized vocabulary (your unique go-to words that identify your writing).
Are you actually tired?
Go to sleep.
If not, shut down that excuse! Nothing great was ever made blissed out on a cloud. Creating is destructive. You sacrifice a piece of yourself to bring forth a work of fiction.
If you can read this, then you already know about story structure. Do not fall into the trap of conflating the ability to articulate story theory with the ability to craft a compelling fiction.
You discover yourself not accomplishing what you declare yourself to be? You are a writer and yet are not writing.
Slay your dragon and free yourself from the fear holding you back.
Starting is the toughest part. Inertia is the strongest force in the universe to conquer, and if it took billions of years to produce your ancestors, why should it be any smoother for you on your writer’s journey?