Have you spoken to a therapist about this? They may be able to help you work through your anxiety and enable you to make that big step in time. Cbt might be a lot of help in this situation. Perhaps slowly working toward it with a professional could help ease a bit of the day to day anxiety too. Knowing you are working towards it that you are doing something could help. When the time comes it might also help to have a friend or sister or daughter or someone who you can use as a support system that can be with you.