Some great advice. For me, content is never an issue as so much of what I do tends not to follow the prevailing current.
What I do struggle with is formulating a concise outline of how I want my material to be presented.
I will give your method a try as the 5 minutes and 50 or so words it would take to organize my thoughts sure seems like a good investment of my time.
I hope that as time passes your health improves and you find yourself in a better place.
Although all that you have gone through over the past several months may have made it more difficult to write, you would never know it when reading your final draft.
Try it and then break the words into themes that have a logical flow.
Draft? :P I freewrite for the most part and what I struggle with now is tying off ends and bring it all together. Normally, I end back at the start after exploring a little in between. it is a struggle to not leave threads hanging.