How do i tell him??!!?

there is this guy, we are like best frnds for like 5 years already.at a month ago he told me that he has feelings fr me n that he cant hide it anymore, and i told him to forget abt it n that we r only frnds(rudely). i went for a vacation for a week, and there, all kept thinkin abt was him! n then i realized that i had feeling for him too! now i dno how to tell him that! i turned him down soo meanly n am afraid he does that to me to as a revenge! =( HEELLP!