Heh, been there!
I'm guessing you neglected to hold-over enough. At 5 yds, your POI will be almost as far below your POA as your scope's centre is above the center of your bore (barrel).... For me, that's about 1.5", and my holdover would be about 1" of holdover at 5yds... I'm sighted in for 20yds.
Better luck next time, Ratty'll be back!
J