Author James Michener once said, “I’m not a very good writer, but I’m an excellent rewriter.” I’m not certain of the context, but I take this as him waxing philosophically over originality. It’s often said that Shakespeare used every emotion and plot device leaving nothing left for any other writers. The only details that change in new stories are the locations, technology, and cultures.
As someone looking to start writing, it could be discouraging to approach your medium with the belief that anything worth writing has already been written.
I’d like to encourage you to stay with it. Apple didn’t invent computers, they simply make them. Toyota didn’t invent cars, they just build them. The difference? Both strive to do it better than it’s been done before. Don’t let others’ accomplishments and victories keep you from achieving your own successes. Just try to be better.