You should call your schools and find out where they want the transcripts sent from. It's hard to guess if they prefer your grades from you or your school. Speaking of which, how badly did you do?
I would imagine that you would have to have less than a 2.5 in order to be disqualified from a Carribbean medical school (even if it's the big 4 - I do know that most US medical school will let you slide with a 3.0 once you've been accepted).
Besides that, how do you know that you did badly? You don't even have your transcripts, maybe the course will be curved and you'll end up with a B or A-