Communication difficulties with advisors - starting to impede work
I think the core issue you are describing is relevant for many PhD students. Your mental health may excabate the effects, but does not seem central to the situation to me.
A PhD is a journey through uncharted territory, and that can feel uncomfortable. So in particular for industrious students, there always is a temptation to to not go where the dragons are yet, but to prepare just a little bit better - maybe read another paper for the literature review, revise the project proposal again, those things. But even within a single field, it will almost always be impossible to read all potentially relevant literature. At some point, a PhD student just has to take the leap.
For me in math/TCS, its just my own time which is on the line when doing research. Sure, maybe if I had read another paper I'd have seen that the theorem is already known, or found an incredibly useful ingredient to make the proof easier - but the time I spent trying to proof it still isn't wasted, as I learn from how I tried it. I'll concede that if you are eg doing experiments with animals or expensive chemicals, you do need to prepare well - but the point remains, at some point you need to do.
Polishing aside, you have 100 pages worth of research proposal + literature review. That is an enormous amount for what I am used to - 30 pages already seems pretty extensive to me. For a supervisor, getting a student to take this leap is something you can influence only in a limited way. So I can empathize with your supervisors frustration (although this doesnt excuse the mean remarks).
When it comes to the issue of preferring to have multiple active tasks, and to work on the best match to one's current mental state: I share that preference, and I think it is explainable very well without referring to any medical diagnosis. The moment to bring that up probably is once you have completed your designated task; and you should make clear that you understand that these tasks need to move you forward.