So really out there, but I've just watched "Your Lie in April" anime and the piano artist has some kind of anxiety attacks while playing the piano, and the symptoms are very similar to what you describe; suddenly things turn gray under-water-like and start turning and his view/hearing of what he's playing disappear, see min 1:32 here:

https://www.youtube.com/watch?v=41tIxqieC0c

I couldn't find any illness associated to the condition of not being able to hear yourself/the notes disappearing while playing, but what you are describing, losing yourself while reading as the world closes around the words in a kaleidoscope-style prism, sounds really similar.