Sooner or later, the ideas will begin to take shape and whole paragraphs will start to appear. Getting something down in writing gives you ideas about how to improve what you have said and where to go from there. Be your own editor. You should act as the first friendly critic of your own work. As an independent scholar, you are responsible for correct spelling and grammar, the application of the conventions of scholarly writing, and the clarity and persuasiveness of your ideas.
Polished writing is the end result of multiple drafts and fine-tunings.
It is not unusual for the refining and editing of a scholarly paper to take as long as writing the first draft. Reading your work out loud to yourself will also reveal where continuity of ideas or development of an argument might need some adjustment. Use iterations as learning opportunities. A request for further iterations of your work is not an indication of failure but an opportunity to strengthen your work by extending your ideas or reaching a higher standard of thinking or communication. More than one iteration is normal, and several are not unusual.