not feel yourself
not feel (oneself)
To not feel physically or mentally well; to not feel as one normally should. I'm sorry for getting upset at you earlier. I just don't feel myself today. I know Mary hasn't felt herself ever since her cousin died.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
not feel yourˈselfnot feel as healthy, happy, etc. as you usually feel: I don’t feel myself this morning; I think I’ll stay at home.
Farlex Partner Idioms Dictionary © Farlex 2017