feel like oneself
Also, feel oneself. Sense oneself as being in a normal state of health or spirits. For example, I'm finally over the flu and feel like myself again, or He doesn't know what's wrong but he doesn't feel himself. The antonym is not feel oneself, that is, “feel unwell.” [Mid-1800s] Also see feel up to.
feel like new. Also, feel like a new person. Have a renewed sense of well-being, especially after something has happened, such as recovery from illness or receiving good news. For example, The surgery went very well, and he now feels like new, or I am so relieved at the news, I feel like a new person.
feel like a million. Be in the best of health or good spirits. For example, After winning that prize I feel like a million. The million alludes to a million dollars. Also see look like a million dollars; on top of the world.