You’re going to run into it eventually. If you stay on the creative path, it’s going to be inevitable.
“They beat me to it.”
I’ve been creating stories for a long time. Since before I could read, and once I was able to read, my stories have only gotten better. I remember being in elementary school and I had a character named Puma. He was a shapeshifter. I don’t remember if this was before or after the show Manimal. All I remember was being simultaneously upset and proud when Marvel Comics debuted the Puma in a Spider-Man comic. They beat me to it.
There are three things to do when this happens. The first thing is you can continue on, acting as though the other work doesn’t exist. This is a viable solution, because not every story is told well, not every story will be a classic, and similar themes are all over the place.
The second thing is to abandon the project. Sometimes things are just too similar for comfort, and if yours comes out after someone else’s, then you’d be called a plagiarist at worst. I had a story that I abandoned for a while because some elements were too similar to another creator’s story. When things are very close, this can also be a viable option, depending on how far along you are. If you’re still in scripting, then you can put it aside for a while. If you’ve already hired a team and they’re working on the story…then you have a decision to make whether to continue on or stop production. That’s a decision only you can make.
The third thing is to change the elements of your story in order to put some distance between you and whomever beat you to it.
No matter which course you decide, don’t stop creating. The first and last see you continuing to create. If you choose to abandon the project, then start a new one. Create. It’s important, because these are stories only you can tell.