Marriage

My best friend of over 7 years is getting married next week.
Living in Utah is really strange, yet I've lived here my whole life. It seems strange that all the young adults are getting married right out of high school or in their early years of college. My friend is only 19. She has her whole life ahead of her.
I don't want to say anything to her because I don't want to push her away. I just think that she's not really thinking about how this is going to affect her life. Her fiance is a few years older than her. He's been on his mission and it has been 2 years since he's been back, but she still hasn't seen the world.
She had so many plans for after high school. So far she's gone out of state for school and volunteered to teach little kids in Russia. It's a good step, but for her it's nothing. She had so much she wanted to do. I hope that he won't stop her from reaching her life goals.
This whole experience has been really hard on me. I can't wrap my head around this event about to occur. My level of anxiety has reached max level. I'm having new symptoms and it scares me. Usually I lock myself in my room and cry it out, but now my palms are always sweaty and my heart races at a million miles per hour and sometimes I get hit with nausea. I began taking half of my mom's medication to see if it would help me. It has but to a certain extent. I might need to go back to my doctor and see what they can do for me.
I just don't know what to do. I guess nothing. Just sit back and support her the best I can.