I don't know if my response will be helpful and I apologize if it isn't. I lost my Grandpa almost 8 years ago and I have simailar feelings like guilt, sadness. Grandpa was my abuser and I have this love/hate thing going on inside. I also wished he died when he was alive. I numbed my pain with alcohol til 3 years ago and I did not grief.
I think it's hard to grief when it's so complex. I hope you can find some help through this Hugs