AoPS is great, and the Math Circle at Berkeley is especially good. As far as math goes, you could google a current Harvard Senior from Danville, Evan O’Dorney- it is a real joy to watch You Tubes of his “who wants to be a mathematician” stuff. He also was home-schooled and did not go off to college until he was 18. He won the Intel, he has been a “Putnam Fellow” (top 5 scorer) each time he took the exam. He medaled in the International Math Olympiad each year of High School. He won the Scripps Spelling Bee in 8th grade.
I hope you re-think the Ross program (in Ohio). It would be great fun for you. It is not competition math- it is like intense math circle.