What do you do when the story that you are trying to tell is almost identical to a different story that you didn’t know about and do you cannibalize your own story to try make it seem more original?

I don’t know what to do with this story that I tried to write and it is a problem that I never had to face before. I am used to being able to write a story and not have to worry about this. It seems like I have accidentally come up with a story that is almost identical to a different story and it is really frustrating to think that it is no longer original. I don’t know if I should cannibalize the story and take out the things that makes it the same as the other story and turn it into something else, or do I leave it as it is and try to make the two stories more distinct. I am feeling very frustrated after everything that I’ve been through and I don’t know if I should start over or just abandon the story completely. I’m not exactly sure what to do in this situation.