I have been in content marketing for over a decade and I still get this feeling regularly. You come up with something you are excited about, start researching, and find someone already did it, sometimes better.
But here's what I have learned: the format or idea being done does not matter nearly as much as your specific perspective on it. Two people can make the exact same type of video about the exact same topic and one resonates bc of their personality, timing, or angle.
The ppl who actually build audiences are not the ones with the most original ideas - they are the ones who show up consistently with their own take. Your lived experience, your taste, your way of explaining things. That is not motivational fluff, its literally how content algorithms work. They are optimizing for engagement, and authenticity drives engagement.
My advice: stop waiting for the perfect original idea and start posting. Your first 50 pieces of content will probably not be great, and that is fine. You will find your voice by doing, not by planning. The fear of unoriginality is just your perfectionism!