Your idea is really interesting.

I rarely (if ever) comment on my mental health online, but I can totally relate to a X-Y quadrant as you describe. Many mental health professional debut their appointment with a dreaded question "how are you feeling today?".

If I had this diagram with me, it would save time and be way more descriptive of my state of mind.

As for the high unhappiness/high unhappiness quadrant: I'm not manic myself but know close ones who are. I think it fits.

Thanks for opening my mind about this.