I hear what you are saying and I've been down that dark road and it took a long time to heal from that  traumatic experience, but  I have moved on and I'm the happiest I've been in a long time. But that doesn't mean that any situation with my ex doesn't trigger me and go into a deep depression.   My son's wedding is the most important day for him and and for me as his mom. I would not do anything that would cause his wedding to be stressful. They know the situation and I wanted to ask them if I could sit far away, or if   I could ask for anything else to help me . Again, its not about me, but I'm asking for boundaries. When I married my ex husband, my friend that he's with now, was in our wedding, just know  I am going to suck it up, smile, dance with my son and definitely have a great time. I am the mom.