Sweetheart
You don't deserve this. It's not your fault. I know your mind knows this of course, but your heart will always need to be reminded.
Be kind, gentle and nurturing to yourself. That is what you deserve.
For the record, I think you have every right to demand the information that might save your life from your mother, but not at the expense of your heart. Think of the scenario: you lose your right mind in a bitter battle with an ex husband...your daughter needs something from you that might save her life...you are so hurt and bitter you try to block her...
What would you want her to do?
Or, in another scenario, you are played by your best friend? What would you have her do?