That fact that you are being so open about it is going to help people. Sometimes people gets abused for years and years and aren't aware of what is happening and how it effects them. Some might see your story and realize that some of their problems are caused by others. Sometimes things that are triggering help us grow.
My anger ruined me too. I was very angry when I made my attempt. I was angry because I was broken down and over my head. Anger is a sign we need to seek help and/or change our lives.
As for your mother helping her mother--times have changed. And I wonder if you mother helped her mother on her own terms to some extent (who knows). Offering to help her apply for medicaid was not an unreasonable way to handle it. It is hard to help people who are hard headed, manipulative (liars) and mean. It sounds like you have done a lot for her throughout your life.
I am sorry you are going through this--of course you are sad. All of our actions have consequences. All that matters is that you work to overcome it and manage to find peace. I know you are a very kind person. It sounds like you outclass her in that regard. And mostly you are just so cool!!