So sorry for your loss. I feel your pain and your mothers pain. I see someone crying. Your mother does love you though. despite it feeling like she totally abandoned you and forgot you existed.
Hiya OP! IME when there’s glaring gaps information, it’s a ‘hint’ that you’re supposed to unravel the whole tread and figure out what’s missing. Time isn’t linear- aka it’s possibke for you to astrallly visit your dad while he’s alive, or do magic on/in the past to learn about it- so unlocking the past may hold the key to the future. Reality is awash with uncertainty! You can use it to your advantage if you try.