My mother went through a crisis a few years back. Within the past 6 months I have spoke to her about it from time to time. I was the focus of a lot of her anger. She spewed at me on many occasions.
I spoke to her recently about how she felt and what was going on. Everyone is different, but she did say she thought about me and the kids everyday. The guilt she had was unbearable. She couldn't sleep at night and she wanted so bad to see us and say how sorry she was, but she was so affraid of how we would act or what we would say. In here mind she thought we would never forgive her.(this was when she was further along in all of this)
It took a huge amount of time to get to where she is today and she still has days where she can't even believe she said and did the things she did. It takes time, for both of you.
Love her from a distance and don't give her any reason to view you negatively. Look at her anger as a sign that she is moving along in this crisis. (It sucks but it's progress.)
Hang in there my friend, stop looking for the finish line and focus on the steps you will be taking today to move you further along in your journey. Today is all we really have anyway.