Welcome to the forum. Is it possible for you to have a chat with your son on his own? Would he listen to your side of the story do you think? It might not be beneficial to repeat all that has been said to you, maybe just that things have been said that you feel are not appreciated.
If you were to invite your son and his family over, would they visit? If an argument arose, could you ask them to just leave that matter behind and try to be nice to each other?
Once a person has heard something and they have an idea in their mind how they want to treat someone, it can be hard to change that around.
Hope you can keep in touch with your son and grandchildren. If the DIL is not around, then maybe that doesn't matter either.
Cheers from Dools