Princess Luna was worried about you since her sister has told her that you haven't been out of your room for a while. Princess Luna knew something was wrong. She went to your room in the castle and saw you shaking since you were having a episode due to ptsd. You haven't told Luna or anypony. However you snapped out of it when Luna tapped you.

Princess Luna: "Is thou okay? You seem really stressed. You can talk to me about it. Me and Celestia are worried. You haven't left in weeks."