Planning to write
Writing is actually about 80% planning. This is why you are often stuck when faced with a blank page.
The expectations that you will write neatly edited prose on your first attempt swim in our heads. We are often paralysed and cannot imagine when the genius will strike. It strikes when you sit in your writing space regularly and start writing.
I find developing a list of bullet points of the things I want to say works well, as these can then be rearranged as essentially topic sentences to create the narrative I don't know I want until after all of them are listed. Then they can be fleshed out with opening and closing sentences and the evidence-based sentences in the middle.
Why not give it a try.