This happens all the time. There aren’t really anymore original ideas. I’d say if this is the idea you’re passionate about, keep writing. Then revise and query. And then start working on something else.
I have been working on a novel for a while now--an exciting idea I haven't seen before in YA, however a book has just been published by a well-known author that is uncannily similar! Not exactly the same, but it makes my book seem less original. Should I scrap it and start over?— Anonymous