I was moody. Extremely moody. I was angry at myself. I was depressed. I had very little motivation. I didn't have physical symptoms that I'm aware of, it was mental and emotional for me.
What you are feeling will subside over time. Your body and mind are learning how to function "normal" and it isn't an easy process.
Congratulations on 4 weeks, that's phenomenal. Keep it up and you will push through this wall.