Don't let your son guilt trip you. He has to learn to honor your boundaries and perhaps you are being taught patience and that you are "enough" even when you enforce your own boundaries. The reasons they are mad may be more about them than you. You had your reasons for not going to that wedding. Don't second guess it. Try not to continue to rethink it (I know it might be hard but distract yourself as much as you can. ) If your son doesn't understand in this life, he will in the next. It is likely that you and his wife are teaching him important lessons. Some lessons in this life do not come easily. Hang in there--you can get through this. You are in my prayers.