You were born in 1991, which makes you 13 (14 later this year). It has been shown in numerous studies that if you weight lift too early, you can damage the growth plates of your bones. This only really occurs if you do maximal lifting -- that is, if you lifted as much as you possibly could or did any kind of powerlifting.
It's fairly safe for someone your age to lift as long as the weight is moderate and doesn't load your bone structure to heavily. If you lifted weights that were as heavy as you could possibly lift, yes, you may have HURT your growth ("stunted" it) though it's unlikely that you've stopped it entirely.
Look on the bright side... shorter people have more strength-per-pound than tall people - so you'll still be able to hold your own in a fight.