Have you considered international options at all? You’d be a strong candidate for Oxford/Cambridge, although I know you’re young and going that far might not be desirable. On this continent, U of Waterloo in Canada is a tippy-top Math/CS school that recruits top performers in math contests. These options would all cost more than your state flagship, but less than full-pay at an HYPSM-type school.
Your state flagship w/ honors college is a good option. Tough to pass up the super-elites, but it sounds like you have good perspective on how that may not be worth the financial strain.