What would you do? A guy's opinion would be great?

[aly88]

So this kid used to like me back in middle school, and confessed in the yearbook (He wrote "I love you"). I liked him too, but I was stupid and didn't realize it was a confession. Plus, after summer I didn't know how to bring it up. Freshman year of high school he would make pointed flirty comments towards me, but I was super shy and awkward, and didn't know how to respond. We had classes throughout high school, and we talked off and on, but we would be really awkward around each other, and mumble/stutter when we talked. I felt like he was over me, but was just awkward, because I know that he had a few relationships in high school. So, when we graduated, I thought i would never see him again. I told myself I was over him, & I believed I was, until I saw him on campus in college. I've had crushes other than him, and talked to other guys, but none have given me butterflies the way he has. So freshman year I ran into him, and we talked a few times. Finally we were no longer awkward around each other. Last year we lived in the same dorm, and would always say hi when we saw each other, and we also held a few convos. This year he left college to join the army, but I keep having a nagging feeling like I want to tell him that I like him because you never know what's going to happen, and I don't want be left wondering. I'm just not sure if I should because we were never really friends, but I know for sure that he liked me at one point, and took my lack of response as rejection. The only method I have to contact him through is Facebook.

My question is:
Should I message him on Facebook & tell him, and if so, how should I without sounding like a total creep? OR whether I should just let it go?
I would like a guys opinion on this, super appreciated!