Jesus I'm sorry that bomb exploded in your life.
Those kinds of betrayals cut very deep. My parents split at about the same time and even though I am an adult I still haven't gotten over it either.
I don't really have any feuds exactly but there's a whole family I used to be friendly with that I am not anymore. I met them through a woman I worked with while in college. Over the years I got to know each of her family members. After being with my fiance for 8 years, including all dating years, things really began to fall apart. I confided a lot in this woman's sister. She knew some very personal things that nobody else knew. But after I wound up leaving she moved in with him 2 weeks later.
When I found out I vomitted.
That was the most difficult year of my life and I never want to feel like that again. I am very careful about the people I will hang around with now. I barely got through that year. It really felt like something exploded in the middle of my life and I was living in the pieces. I had no home (temporarily with parents), no kitties (he had my girls), few friends and none who weren't somehow related to this woman. It was awful.
Last week my ex was playing a gig. Also a mutual friend of ours was going on as the next act. I really wanted to go but I couldn't do it. It would depress me to see her there and all. So it still does affect me these 7 years later.
Yes, my mother decided to leave my father after I left my ex (while I was living back at home). I was so mad at her for that, still am. Oh man this thread is depressing! But it reminds me of how far I have come because now I am living the life that I want to instead of trying to fit some mold that he wanted me to be.