It’s going to hurt but colleges love seeing upward trends (fingers crossed that they love mine since I’m in a similar situation as you). The point is, colleges know that some people aren’t born to go to Harvard and don’t pull 4.0s from the minute they enter high school. Rather, the reason why your junior year is the most important is because colleges look at that the most- they see the student that you’ve become and the student that is applying to their school. The economics competition is a very redeeming quality. Also, the exam marks coupled with internal school grades could just signal to the adcom, for all you know, that those classes were taught by a poor teacher but ultimately you did very well on the actual exam. Just for a point of comparison, I got a B+ in my AP European History class in the second semester of my sophomore year, but got a 5 on the exam. So this shows colleges that the class was difficult which is why I didn’t get an A, but I was good enough to get a 5 (funny thing is that the people that got As in that class got 4s on the actual exam). Overall, you’ll be fine.