Trust me, there has never been an artist who succeeded at every creative act they perform. I demolished a number of canvases in my early days. One was a scene with a foreground object that required days of tedious airbrushing. We often learn more from our failures than from our successes. Be proud of the effort you have made and keep on trying.
Many useful books are available today dealing with success strategies.
Such books provide wonderful advice on coping with failure. Any praise I can give here cannot do justice to this classic art instruction book. If you are one of the artistically challenged who believes they can never draw anything, I promise you will be able to draw and compose better than you ever thought possible after you finish this book. For generations American children have been captivated by the fantastic adventures and wonderful artwork in the pages of Marvel Comics. This book is a light hearted introduction to comic book art from two of the creators of the modern comic industry.