I don't know how to handle this love situation, help?

I'm pretty new here, this is my first post. I have this super odd situation with my honey, and I don't know how to be okay with it. He and I dated for nearly two years, and he is a year younger than me. When I turned 18, even though we had been together a decent amount of time, his parents immediately disapproved. This lead to him breaking it off and it was so hard for both of us. It only lasted two months and we couldn't stay away. Now we have a sort of secret relationship that his parents don't know about and it's really hard on me. He is such a good guy and he just wants to make me feel better, we only have the half relationship because I wanted to have as much as I could get. We don't want to be apart, but I don't know if I can keep being half in, and I can't pretend I'm just his friend. He turns 18 in four months, so it's not long, but it's so hard to be separate from my love for over two years and my best friend since junior high. I know this sounds cheesy and dumb, but I know he's the man I'm going to marry. When everything feels wrong and screwed up he is always there and the one thing I know is right in my life. We have fought, but never yelled at each other. The way he and I communicate is just beautiful. I know I that there are billions of people in the world, but I don't think anyone could make me feel or laugh or love the way he does. I don't really know how this all works, but I guess I'm just looking for advice on what to do here. Haha thank you to everyone that read all this! I know it's long!