This was something I’ve noticed since becoming stable from meds a few months ago, when the months of crazed thinking subsided and the burnout set in. There’s been hardly any highs or lows since then. Along with the weaker cognitive ability it’s the lack of feeling that disturbs me. It really makes life rather pointless, which is how I’ve viewed mine for quite some time.
Welcome to the club … what you describe closely matches my everyday life since 2014… hang in there, we need help and help is on the way 
I feel as though my feelings have burnt out as well. I don’t really feel much now except irritation, fear and when I’m not doing well depression and pain.
Along with this is a reduced attention span and lack of interest in almost anything. It’s weird because I used to be able to get engrossed in reading or videos, and now that seems gone for good. And I’m constantly seeking something for distraction but can’t easily be entertained.