Happy to hear that I am not alone in my boat. I have been struggling I must say. I think that there is not any worst suffering, for people like us, who value learning and want to keep at it, there is nothing worst than brain fog and the impression that you are loosing your faculties.
You are up to the last part? That sounds great. Every time I felt like I would not get there because brain fog was back, I would picture myself, almost on top of the mountain, to get courage from realizing all that I had been through already and the little left that needed to be done.