feel oneself

verb3

1. •
   (informal) To feel comfortable or normal; to be in one's usual mood or state of health; to feel like oneself.

   • I hope you don't mind if I cancel our date this afternoon – I just don't feel myself today.
2. •
   To touch oneself.
3. •
   (informal) To feel particularly good (especially about oneself) or particularly into oneself.