Just because a lot of H.S. relationships end, stop acting like for sure it's going to end. That's just a rumor that like 99% do. It's only like 60%.
I would check the statistics again. After many years of doing "stuff" I can honestly say that I cannot think of one single person I have met in the past 10 years that has actually married their High School sweetheart and is still with them to this day.
Not one.