I applaud your efforts Jammy. It’s so painfully obvious that the hurt inner child desperately needs answers. For all the reasons I stated previously, I doubt you will get totally truthful ones from the only person who could give them to you.
However, listening to the depths of your despair, maybe the only thing left for you IS to approach your mother. I advise that very reluctantly, and hope that your already very damaged psyche can take it. Please think long and hard, face the truth that it may not give you what you need, imagine what your worst case scenario would be from such a confrontation. Then attempt to find the strength and courage to go ahead and face it.
I hope you find some peace, however small.