S.S.
My little boy just turned 4 two weeks ago. He is registered to begin pre-k next week; but the closer it gets, the more we think he's not ready. He's never been away from me a single day in his life, and pre-k is 7 hours per day, 5 days per week. He is not completely potty-trained; and I think, at this point, it is just a test of wills. He knows how to do everything; he just won't do it. I told him earlier this summer that he couldn't go to school unless he got potty-trained, thinking it would be a motivation for him. Instead, he said, "Good! I don't want to go to school!" So now I think he is refusing to go to the potty because he thinks that, if he isn't potty-trained, then he won't have to go to school.
I don't have any advice for you or your little girl (obviously, I don't even know how to help my own child with his fears). I just wanted you to know that this is not unusual. I think many families go through this kind of behavior in one way or another. My only inclination is just to keep loving her and hugging her and kissing her and being there for her. And don't discount her fears or make her feel stupid or unjustified. Encourage her to talk about what scares her and then just listen. Give it time.
I hope it all works out for her (and you). Blessings to your family.