You have lost her trust, now it will take time to reestablish her trust in you. Unfortunately you have given her reasons to be insecure and now that insecurity is worsening your relationship. To win her trust again, rather than reassuring her all the time you should be honest in your dealings with her. Over a period she will realize this. Do not go on doing long discussions on what you did or what you are going to do. Just let your attitude speak than your words.
She also needs to work on her insecurities.