Suggestions for coping?

I could use some help with deciding on some coping mechanisms. My boyfriend is getting married in a week and a half and I'm super excited for him and his fiancee. She's great and they have a really solid relationship. I'm not used to feeling jealous and I'm really not experiencing any jealousy specifically about the wedding. However, she will be taking his name and that is driving me insane. I'm at the point where I'm too nauseous to eat and can't really sleep. It's not something I can change and I can't figure out a way to be ok with it. How do you cope when there's something you are patently not ok with but have no influence over? I feel like I'm gasping for air with my head shoved under water.