Missed opportunities with romantic possiblities in the past?

This almost set in that the person I like might be leaving to a different school, career center, next year. I just finished my sophomore year today, and my only exam I took was with my crush. He would always stare at me and we'd have long gazes, but he didn't show anything that he's truly into me, so I didn't want to pursue anything at this moment. I don't want to regret not even trying, because I've liked him since 6th grade. It's so difficult, because I don't want to tell him and him tell everyone, and we're not super close. It's so stressful and I have no idea what to do.