I snapped!

I like to think of myself as a pretty rational person who gets along with everyone. I have the physical barrier of being fat that I have to help people overcome before they realize I am a fun, likable person. However, being fat has always been my nemesis and is something I am not proud of. I have battled my weight since early childhood when kids in school were so willing to bully me, exclude me, and call me names. Mostly I have been able to set my insecurities aside, roll with the punches, make friends, and find diversionary activities which helped me develop my self esteem and sense of self worth. I found talents through my weaknesses that helped me develop the successful person that I am today. By no means am I at my goal weight, I will forever be working hard to get there, but I can say I like the person I am despite the fact I don't like my size. That being said, why is it so easy for me to snap mentally when someone call's me a fat "b--ch"?!
This weekend I was not feeling well. A head and chest cold accompanied by nausea plagued me during this beautiful sunny weekend. Despite feeling sick, I decided it would be all right if we spent the afternoon having a late lunch with my mother-in-law. Lunch went fine until the end when my mother-in-law got upset over some words exchanged between her and my husband. She wanted to find her own ride home. I tried to smooth over the situation and convince her to ride home with us, but before I knew it, she was attacking me personally and calling me derogatory names. I allowed myself to stoop to her level by getting upset over her words and said hurtful things in return. I then proceeded to walk away with my baby in my arms when she shot an arrow through my heart by calling me a fat "b--ch." I came unglued and charged at her, almost punching her. I lost my cool and threw a plastic cup at her, never meaning to hurt her, only to scare her. This 20 ounce empty plastic cup left a one inch gash on the top of her head. I feel like a complete idiot! I let her get to me, lost my temper, and am now paying the price for this split second decision to throw a cup at her. I lost any dignity I had when I did this. My dignity would have been kept intact had I just continued to walk away while she yelled at me, making her look like the idiot.
One thing said....... I have learned my lesson. She brings out the worst in me and I plan to stay away from her for as long as I live. She has serious psychological issues and will never find happiness until she starts liking herself and stops blaming others. I have just dealt with 15 years of verbal abuse from her and FINALLY have had enough. I snapped!