Why exactly are you interested in boarding school? To take the most rigorous math classes? Seems like a silly reason to attend BS, in my opinion. If you want to take rigorous math classes, then just stay at your current school and then take courses at a nearby community college.
Based upon your flippant responses, it sounds like you wouldn’t do well in a BS environment. All of the other parents have already chimed in, so I wish you the best. Hope you find what you’re looking for.