Understand fear. Emotions can be hard to regulate when they get high, especially when there isn't anything put in place to help. Perhaps you can do something calming like color or watch a movie or something until the fear resides some. Maybe write down what you are afraid of and really consider if you are in actual danger or not. I know it's hard, especially if flashbacks are involved in the fear. When you aren't in a state of fear, it's is a good time to practice some things that will help the next time.
Take care.