Even today, at 72, I cry about not having been able to "reach" my (long-gone) mother. Today I realized that, although I failed to reach her, heal her, make a better connection with her, or obtain the nourishment I needed from her, it wasn't a personal failure. It couldn't be done.
For some reason, that helps me grieve more cleanly. I can see the possibility of moving through the grief to the other side. Something like, "It wasn't my fault, so I don't have to keep trying to fix it."
I hope this will be the case. At least it's a start.