Your daughter can sense your anxiety. I think that it is always better to talk about these things with your child in simple language. Children look to their parents to get the message that things are okay. Your anxiety and lack of explanation tells her that things are not okay. Can you tell her that you have a problem with nervousness and that you are working on it and it is all coming from your past problems and that everything today is okay? Maybe do some relaxation exercises and/or cuddling with her and tell her that everything is okay? How about telling her some stories that can help her to escape to a calm place? It will be a special thing just between the 2 of you?