Hey man, fellow creative here that barely feels actually creative.
I'm the same way in that it's hard for me to doodle or randomly come up with stuff. The blank page is my worst enemy, and I do best when I have something to work with. If you ask me to fill a page with something random, it's not happening. Ask me how I can solve a specific problem or how to convey a scene visually? That, I can chew on. And I think that's where our creativity comes in, assuming you're similar! Don't feel bad about that.