Maid Of Honor

My best friend Katarina (not her realname), has recently gotten engaged. Although we drifted apart after high school, we have still stayed in touch and up to speed. She moved to Virginia to start her career, I moved to New YOrk City to do the same. Last year, one of our girlfriend`s from high school got married and she was asked to be the maid of honor. She was very surprised at this because Katarina and Kristy were not very close. AT the wedding, Katarina pulled me aside and said...I was really surprised when Kristy asked me to be her maid of honor. I live so far away (the wedding was in Syracuse) and we were never really close. When I started to think about a speech and all that stuff, I couldn`t help but think of our friendship. I didn`t have the memories with Kristy that I did with you. I can`t imagine wanting anyone else to be my maid of honor when I get married. I was really surprised because I knew that we had drifted, but i still considered her very close and very important to me. I was relieved in a sense because i Knew that i always wanted to ask katarina to be my maid of honor someday. Katarina`s mother and I are very close as well and we spoke about the wedding too. She said she couldn`t wait to coordinate everything with me and she would start gathering old pictures to create a scrapbook. This past June, Katarina still wasn`t engaged, but we were expecting it. It was her birthday and I called her. I asked if she had received any "special presents". She didn`t, and at the end of our conversation I said...I can`t wait to get the phone call that you need a maid of honor. She replied with I know, I can`t wait. On July 13th I got a voice mail...Mandy, I wanted to letyou know i got engaged last night and i wanted to ask you to be a bridesmaid. I dropped the phone, i was hysterical. I pulled myself together to call and congratulate her. I tried to hint to the situation, but didn`t want to stress her out. She said, so, are you going to be in the wedding? i replied with yes, but was absolutely devestated. Nothing was mentioned to me. I worried about the situation for 3 days until i decided to call her mom. She told me Katarina decided to ask her 16 year old half sister who lives in syracuse. I`m absolutely devestated. I`ve been crying and worrying for days. I don`t know what to do. I`m not sure if i will feel comfortable being in the wedding party. I asked her mom how Joanie, her 16 year old sister would throw her a bachelorette party. She said, that`s what i`m for. I`m the #1 bridesmaid. I feel like i was betrayed, slapped in the face. Katarina is the only girlfriend i have that has never stabbed me in the back, now i feel like i`ve been completely betrayed. I wish she would have talked to me about it. She still hasn`t said anything and it`s been 6 days. What do i do? i`m so torn...am i being selfish by not wanting to be in the wedding party, or should i suck it up for my friend?