Nope, not cold at all.
Maybe it'd help to tell her how she hurt you when you were younger, just to get it out in the air and let her know how you're feeling and how you felt then. I mean, you're both 18 and I think you can maturely talk about it without causing a fight or whatnot.
If somehow you grow to be friends again, that'd be cool...but if not, don't worry. You're different people now and it's not like you're required to reconnect after all these years.
You can't live in the past, because you've got to live for the future.