It sounds like you feel betrayed because your Dad kept such an important bit of news from you. And had you known she was that close to passing you could have at least called and had some chance at last words to her that way.
Maybe what's still irking you is that you still have to deal with your Dad for what he put you through.
While his actions compound the loss of your Grand, because you weren't ready to see her go yet and when you get home you find she's gone. And it was kept from you the whole time it was happening. So now the only one's left to face for their responsibility in doing that is your Dad.
Meanwhile, if your Grand was suffering and you believe she's at peace now at least you have that. Meanwhile, I think her spirit can always hear you. If we believe God hears prayers why can't those that were part of us in this life hear our prayers too?
My Grands were both killed by a drunk driver when I was a kid. They were my favorites. I come home from school and my mom, and they were her parents, asks if I want to go visit them?
I'm ready to go because she's already packed me up. We drive for a day and right before we get to their house I get the news.
That tore me up for years! I was so excited because we were just around the corner now and smack! They're dead!
I was devastated. Years later after crying jags, breaking down in church when certain hymns like those that were sung at the funeral began in my own church. I was an emotional wreck. Betrayed by my parents who in their mind didn't lie when they asked if I would like to see my Grandparents, because I was going to get that chance. Only they were in their caskets! Not in the house I adored.
Knowing my parents kept it all from me because they didn't want to deal with my grief for the whole ride. I was torn between broken hearted and really ticked off.
I swallowed it all when it came to my parents. But for not getting to say goodbye to my grandparents I healed that part of it by writing them a letter. It took days because I had to get it together and think of everything I wanted to say between the emotional breaks, but I got through. And then on the anniversary of their death I took it outside and tore it into pieces and let it go on the wind.
I dream of them now and then. Grandmother is always happy. Trying to help me with the gardening. Grandpa is sitting in his rocking chair tugging on his pipe smiling softly and watching us get dirty.
I cry when I write this. But after I did that with the letter I never went into the weeping stages or broke down crying in church again. I guess they got the letter. And maybe being relieved of the emotional sag I was in was their way of sending me their love and that it was all OK. They didn't want to leave. But they knew I loved them dearly.
My parents died a few years ago. Now I weep for them now and then.
I think what it all boils down to is we have to forgive and we have to remember through experiencing regret that we can not change, that when we have the chance we should make sure we don't have cause to have regrets in future.
Even if we can't say goodbye for some reason, the person we love should always know if anything unforeseen happens we love them and will miss them dearly. And I think if that's how we feel and they know that and feel the same for us, that they don't need us to say goodbye.
They know as they're leaving, even if it's for a split second in that crush of metal and screaming breaks, that they're going to break a lot of hearts that held them tight there all the days and beyond even that moment when goodbye happens all by itself.