You don't fear her. You fear further divide from her. According to attachment theory, your reaction is perfectly normal. So recognize your reaction as perfectly normal, but don't lead with those emotions. Lead with your head. Your head knows that what you are feeling is normal, but it is defeating you at the moment.
Go read Navy's latest thread. Go get a book on this topic. You'll understand perfectly why you are feeling the way you are feeling.
But understand that MWD is asking us to get into our intellectual mind and start dealing with our situation from there. It is so hard to do. I got it. But it is important.