My Dsis is getting married in a few weeks to her partner of seven years. After the first couple of years of them being together, she frequently came to me to talk about the problems she was having - he was controlling, had anger issues. She also cheated on him a couple of times and confided in me about this.
My Dsis and me had always been very close but over the last 5 years things have gone downhill. This is down to a number of issues including her partners behavious towards her family (insulting my mum, me, and and my child). Dsis has constant meltdowns at me if I try to raise any issues to attempt to resolve things. Before Dsis and her DP both fell out with her, they accepted a large amount of money from our DM when she was newly bereaved (Dsis is the golden child).
Our once close relationship is now at the point where she barely makes an effort of responds to my efforts to meet up. If / when we do she either cancels on me or brings DP along with her to meet me which makes things very uncomfortable for me. I have asked her not to do this again which has meant I see her even less. I'm pretty sure she's making problems with some of our mutual friends as well because I get dirty looks from people who know us both and were once on friendly terms with me.
The wedding is in a few weeks and I have not been included or invited to any of the pre-wedding stuff - the engagement party, hen do, or dress shopping. I'm not a bridesmaid and there are 5 others who are. I have felt really shit the last few months hearing about it all and being excluded, and I have said that I don't know if I will be in town that weekend to try to avoid the whole situation because I am so hurt and done with the whole thing.
I'm aware that not going will probably make things worse, but I can't face it. I feel like I'm complicit in something I'm very uncomfortable with, and that taking my children along as well would mean that he's got away with insulting my child and her family. I feel sick even thinking about giving him a hug on the day. But, it's not about me and she's very upset that I may not go. How do I navigate all this and not make things worse, while still keeping my mental health and integrity intact?