@Assprin For me, I've exercised creative output in several ways over the years.
Hand-drawing was the most difficult for me because of finding the motivation for it. It was easy to lose confidence because I would get all these ideas for drawings, but I always feared that my inadequate skill would mean I wouldn't be able to do the ideas justice (as if I had one and only one opportunity to draw that idea). But I won't improve if I don't practice at all, so it becomes a catch-22.
EDIT - I forgot to mention writing / fan fiction. For a time, I strongly insisted on having completely original ideas for everything I wrote because "who wants to read something that someone else has already written about before". A friend had to convince me that sometimes, what makes reading appealing is not just the story itself, but hearing it from a particular storyteller.