Kathy, taking a look at how you talk to yourself (your internal self talk) is a good start. Your thinking is that you are a bad person. You automatically assume this perspective and don't consider that you are a good person. What makes you bad? Where did this idea come from? And how does it continue to consume your thought pattern and interfere with any chance you have of feeling good about yourself?
You may have been like a crazy person with your daughter, but considering the amount of stress you were under, it was not unexpected. You were dealing with things that few people have to deal with and you dealt with them all at one time. That would take anyone down. You are going to feel bad about lashing out, that is normal. It is what makes you a good mother. Your daughter knows you are sorry and that it is highly unlikely you would do it again. If your daughter had done this to you, would you forgive her? Take a look at it from her perspective. That will help.