I'd advise to wait. I know you've heard this all to often, but you're too young. You will be going through so many changes in the next couple of years, that as much as you love each other, you may find that your interests will change. Example: You're college age. You would be surprised at the percentage of college students that change their majors in mid-course, when they find their interests have moved on to other fields.
If you are truly soulmates, you will be together, but I have seen far too many couples rush into marriage and find out they weren't ready for the commitment and the stresses marriage can bring. I'm all for living together. I have known couples who were great friends but found that they couldn't stand living under the same roof together.
My own first wife told me years later, that she actually believed that when she got married, she would now live happily ever after. She was very confused and upset when it didn't happen. Of course it didn't help that she was an alcoholic and a secret drinker. I didn't find out until after the divorce.