Well, you do have achance, your SAT score is very good. I would try for Dartmouth if i were you. but this raises the question onto why do you really want to go to an IVY league school. The IVY league isn't special, it was only formed due to the fact that these universities used to have sporting tournaments against each other.
You can go to so many other good American universities, in which you wont have to take even half the pressure. Lets say you got into Dartmouth or Columbia. In those universities you would be average to bellow average. You would be far better suited to go to another university where you can be at the top. So all I need to know in order to advise you on what uni to go to is what subject did you do at AS, and what course do you want to do an uni?