Married at 19

Me and my fiancé have been together since 6th grade(yes I am aware we started dating young) but we have been together for 6 years and he propose a few weeks ago but he is also a Marine and I don’t want people to say you guess are going to get divorced or you are just married him for the benefits witch is not true, but I am afraid people won’t take me getting married to him seriously, including my parents and his parents. My parents got married at 19 but I am still worried. My dad and mom always said don’t get married young wait till you finish college. My parents aren’t divorced and their love for each other is so strong. How did you deal with all the backlash and bad talking about getting married young?