Moving out

Karla • 18
I'm about to be 18 in a week, and my boyfriend wants me to move in with him and his parents. We want to get married after I've lived with him for a few months. I am Mexican and so are my parents and Mexican/Hispanic parents are the ones that don't want to let you go until you're like 25. I want to talk to my parents about moving out and I've already sort of started with my mom and I feel like she will be kind of ok with it, but my dad not so much. I talked to my dad about how my boyfriend and I plan on getting married in the future and he got a bit mad-ish. He likes my boyfriend and all buti feel like he doesn't want to let me go. I don't know how to make my dad understand that I'm about to be 18 and that he needs to let me go. And also that I'm trying to do things right, i want to move out,  get married and have kids. How do I make him understand?