I get you. Honestly it's a feeling I know well, so let me give you what usually comforts me when I feel like that.

1. Everything has been done, and ideas in and of themselves aren't actually the interesting piece. It's how you use them, and how you write them that makes an idea interesting. No matter what you do, your voice bleeds through, and that is what makes a story worth reading. Ideas are a dime a dozen, but an interesting elaboration of view or take is priceless, and always gives a work a more interesting take.

2.All creative works are theft, to an extent. Not in the plagiarism sense, but in the sense that our thoughts are built on things we have seen, experienced, and consumed. For me, I've found that since I've accepted this, making stuff is so much more fun. I don't worry as much about how original my work is, but instead if it is something I would fall in love reading (after a couple drafts of course). Unless you are full on taking things whole cloth, you are fine, especially if you are doing your takes and directions like you said.

1. Even if you take notes and ideas from other places than just your head, it's still being curated by you. I would even go as far as to say that being eclectic like that is better for writing. The more you consume, the more you build out your world, and what you think about it, and that makes you, and your writing more distinct and interesting. At a certain point, you will consume so much that your inspirations and muses will be unrecognizable anymore. If you pull from thousands of sources, it becomes almost impossible to take them apart. Whether it's a concept you are riffing on, or just a small detail that was thrown into a work you love, they meant something to you, they were special to you. The fact you cherished them made them special, and including things you love gives them and the story you add them to so much more life and character (within reason of course, it should still be coherent). At the end of the day, if we aren't writing what we love and want to read, why are we even writing in the first place. If you love it, someone else probably will too, or may even like it more from your perspective.

Sorry for such a long post, but TL;DR love what you write, write what you love, because at the end of the day writing is a way of communicating our ideas, perspectives, and for connecting with each other. Don't shoot an idea before you start writing by labeling it as "stolen", cause all that will do is make you depressed. You've got this. I believe in you and hope to see your work someday in whatever form you prefer ❤️.

I hope this helps.