Here what I'm talking about is 'pain' as a noun, describing something that makes you uncomfortable either physically or mentally.
As far as I know, it is countable when describing physical hurts. Then what about the 'mental' case ? If it's uncountable in that case, can we say 'a piece of pain' in the context that the pain(mentally) may result from different matters or experiences in our life and we want to distinguish them.
Furthermore, if 'a piece of pain' is correct, what is the comparative form of this phrase? 'one piece less of pain'? 'one less piece of pain'?