Engagement - Commitment

So my boyfriend came to visit me at school this past weekend. On Sunday morning, he told me that during the night he had woken up and saw me asleep and almost whispered in my ear, "Marry Me."
I'm 18 and so is he, we go to two different Universities that are 260 miles apart, however he's trying to transfer to my school by the end of the semester, or at least by the end of the year (not only because of me).
The scariest part of the situation is that I would have said yes, right then and there. Neither of us have ever had a job or any type of substantial ground beneath our feets, we've never been on our own before with our own responsibilities until we started school. I'm committed to him as I know he's committed to me. We've been talking lately about marraige and engagement since Sunday. It's not the typical teenaged conversations that go something like, "We're gunna be together forever! We're so perfect this is never gunna end!" Its serious discussion about it and our future.
I'm trying really hard not to be naive, because I'm well aware of the fact that we ARE still very young and this isn't a small matter, but I don't want to be let down.
I'm not really sure why I posted this topic because I don't really know what type of feedback I'm looking for, I don't even know what I'm feeling. It's strange to think, "This is it" ... I'm just not sure how realistic it is.

If you love him, and he loves you and you feel it's right....then all I have to say is..."CONGRADS"

It is very realistic becuase im in the same situation. except im a little younger than you by a year and im married. My boyfriend came up with this idea because he said he loved me so much and he didnt want to be without me and it was hard to believe at first but when time came to it we decided to go and get married. No one went for what we were doing but it was are decision. So if you really love him and you think you are ready for a commitment like that then i encouraged you. Because it really is worth it i wouldnt change a thing for the world. I love him so much and everyday is something new between us. And we are now about to start a family. So think about and you might just want to . But i can admit its not all fun and games all the time but i still love him and being with him.

^Is that legal? Honestly just curious.

Don't believe on him...