vent: how do you let go of the anger?

Post wedding blues: On my wedding day, my sister was arguing and picking fights with me, giving me the dirtiest, meanest looks behind my mother's back and then smiling and kissing up to all my friends and my FH friends. The night before, she swore at me and used the "F" word three times. I could not believe it. She is 37 years old, single, and older....I get that it was hard for her to watch her younger sister get married first, but that was uncalled for......needless to say, I have not spoken to her really since the wedding except for very brief hello on Thanksgiving and then ignored her. I'm still so upset. I could barely look at her across the dining room table.....I can't believe she behaved like a little baby or spiteful spoiled teenager on my wedding day. It was gross and I feel sick thinking about it. She was the worse one.....Actually my widowed mom and maiden aunt were also pretty mean to me the night before my wedding. I am haunted by it now. How do i let it all go?