not feeling oneself
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 feeling oneselfand not feel like oneself
Fig. to feel upset, troubled, or disturbed in some way. I'm sorry I said what I said. I'm not feeling myself today.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.