You are taking the right approach and you have a positive attitude. If you want to change and you want it bad enough it can happen. She is hurt right now but you could let her know how badly you want this. When you are closed other people feel that they are not getting to know the real you. You wall off part of your personality. That is not conducive to a healthy relationship. A relationship needs open communication and intimacy. Neither is possible if you are not there emotionally for that person. I suggest that you get my favorite resource on this subject - mars and Venus Together Forever. This will help you with the problems in the communication area. Let her have a few days to collect herself and then try. Sometimes people are hurt and they will withdraw but then be ready to talk. Then let her know that you are very serious about changing and want another chance. If that is the case be proactive. Don't sit around waiting for her.
Please press accept; this is the only way I am compensated