In high school one of my friends had an alcoholic father. He used to sit in a chair and drink bottles of vodka. Her mom had remarried and made husband a priority so my friend spent her teenage years living with her dad in a neglected two bedroom apartment.
One day as he sat drinking in his chair he stopped living. Just like that. My friend cried for years after and even though I don't see her anymore, I'm friends with her on FB and she is always posting pictures of him and mourning his death to this day.
At first I didn't understand her grief given his parental capacity but over the years I've realized what an incredible need in us it is to have parents. Even if they are completely non-functional, somehow that bloodline creates an unshakable need in us.
I've chatted with you about this JBG and I know you carry a lot of pain with you after all these years. Even with a tremendous step-father I'm very sorry you've lived with this great void all your adult life.
Just continue holding your children and loving them and not taking a moment you have with them for granted.