Nervous about my last minute marriage?

I am 21 and my boyfriend is in the Navy.. we talked about getting married a year from now... but he proposed early instead due to an upcoming deployment.... is it normal to be so nervous?? i love him with every bone in my body and im ready i just feel so jittery and nauseous... it is also going to be a quick courthouse wedding, which is making me more nervous because i dont know what its going to be like to get married in a courthouse ... I just need advice I'm losing my mind and getting caught up in the negative comments about being too young and caught up in all the "statistics"... any advice??