zagor - I don't know how long it has been since you have been out, but your feelings are valid. However, just acknowleding they are valid is not enough - you need to find a way to deal with them - like LadyLee said. If you don't, they will destroy you.
I know first hand, not only with anger from leaving the JW's, but later on when my brother was killed - I had so much anger - it was causing me problems with my husband and my life.
I went to counseling and it really helped. The counselor helped me find ways to confront the anger both over my JW past and my brother's death. I was eventually able to let most of it go. I'm not perfect, I still feel the anger from time to time. But it no longer hinders my life. So my advice to you is to seek counseling. Not only will it help you - but it will also show your girlfriend that you recognize the situation and that you are taking positive steps to solve it.