Sorry about the set back, don't worry these things happen. In terms of co curriculars, school is not the only option. Go to a church or shelter or look up and find some volunteer work, that is always a big bonus. Maybe go out and join a chess club outside of school. Look for things that make you stand out, perhaps learn an instrument and join band, or learn another language? That always impresses. But beyond this, focus on academics, make sure you stand out because remember that their are a lot of people who wish to enter that school and all of them are incredibly intelligent, much like yourself I'm sure.