Pretend that you happen to be an actor. I fully understand this appears to be slightly crazy but try it. Make believe that you're an actor and she's an actress and you're simply actively playing a scene that already includes a script. In that script you go walking up to the lady, repeat your lines, she provides you with her email, after this you accept it and depart. Decide to put yourself in that mindset. Persuade yourself to imagine it thoroughly and play it out. If you continue to have self confidence troubles then it might take a little bit of time for you to recover from it. But that's all it takes is a bit of time and repetition. Just continue to keep trying and at some point you might be able to cure your worry and grasp the art of the approach!