I am so sorry for your situation! I would never wish that on anyone partially because it sounds very much like mine. I made the mistake of asking my DS (in private) to delay the wedding. He told his fiance everything I said and it must have come out even worse than when I said it because now her father thinks that I called her a , hmm, lets say a lady of the evening. No, of course I did not but now I will have to live with that maybe forever. When she heard she moved the wedding forward by a few months. Boy did that backfire!
As for attending the wedding, I did and it was the singular most hurtful experience I have ever had. Don't get me wrong, when I lost my Mom and later my Dad, both of those were painful. But at both of those gatherings people were offering condolences, not congratulations. It was very hard for me to accept their congratulations. It was difficult to feel so hurt around people who were so joyful. That said, I am glad I went because it kept the door for communication open and it let my DS know that I had not deserted him. He knew (and knows still) that I am always here for him.
Don't get me wrong, things have not been all rosy since then. I was still very hurt and resentful of what my DS and DIL had done to me and were continuing to do. That did not change until I changed. I finally decided (way too late!) that my life was too valuable to waste it trying to make things better for my DS especially when my efforts were so obviously unwanted. So I started concentrating on things that made me happy. It is amazing how difficult it is as a mother to shift your focus from your child back to yourself. For some reason we have convinced ourselves that we are not "good mothers" if we stop trying to 'fix' things for our children. Well, in my case it turns out that my attempts at 'fixing' things were just keeping my DS from learning from his experiences. He needed to figure things out on his own. Since I pulled back and stopped offering advice or telling him what I think our relationship has recovered. He is an amazing parent and I honestly believe that on occasion he tells his wife not to treat me so badly. What a turn around! Truly amazing.
As for your question, no you are not being too sensitive but I honestly do not think anything you and your side of the family say will change anything. If it does more power to you. I certainly hope it does not backfire like mine did. If it does, oh well. I remember when my DS told my DH and I that they were pregnant and the first words out of my DH's mouth were "We have got to move out of town". Total shock from both of them. Things have improved since then but still I will never truly love or trust my DIL. Sad, but true. I hope things work out better for you!