Having the recent death of my own father in mind, killed by medications; all I can say I feel with your pain.
I was so angry back then, but then my father`s spirit at the funeral calmed me down; he made his choices, always let me make mine, without judging. It was such a good moment, tears and sorrow, but also a feeling of surrendering, to better forces.
God bless our fathers; they are in peace. All the best to you G, I am sure he is watching and taking care of you.