I recently read two very different books that both emphasized one very similar point -
Stress, frustration, feeling stuck or lost...this is the creative process.
It's something you have to go through to get to the good stuff. We all want to find an easy, step-by-step process for creativity and art. But it doesn't exist.
A solid process is great for the act of research, scheduling your writing time, and goal setting, but when it's just you and the work, it's pushing through the questions and uncertainty that lead to creativity.
So don't give up. None of us have this figured out. We're all in it together. Keep working.