We are still responsible for our behaviour in our bad times, has your wife taken accountability and apologised? You don't say exactly what was said and done during this time so it is hard to advise properly.
I understand that you having this relationship is hard for your wife but please don't stop having it. First it is a point of contact between you and something to build on for the future and second, it is something your wife must make right with your son, you aren't responsible for her poor behaviour and you shouldn't suffer this awful loss too.
It would be very selfish and self centred of her if she tried to force you to choose her side and stop having a relationship with your own child and grandchildren. It would cause you so much pain to do that, I appreciate you live with her and there may be incredible pressure but she must put your needs first here and if she isn't, that's so wrong of her and something to consider further.
I hope you come back and tell us more so we can give some better advise on how to move forward. I'm so sorry you are in this awful situation.
By special request, let’s discuss our favourite Classic Music and why?



