Relationship advice?

So I’ve been with my boyfriend for a few months now officially. We were a ‘thing’ for about a year before and I’ve known him since we were 10. (Both 15 now). He’s a very closed/cold person and very straight forward with everything just like I am. We’ve both (sadly) gone through life experiences that have made us leave our childhoods behind earlier than a normal person would. I could honestly say I’ve fallen in love with this boy over the years. Since day 1 I’ve noticed he was special. We’ve talked about what it’s gonna be like when we start our family and how things are gonna get tough once we graduate. You guys think we could last a lifetime? Because I sure know that I want to die besides him. Any experiences with a relationship like that? Thoughts?