There are great summer math programs. My son did PROMYS. There is Ross. I’m sure at Art of Problem Solving there will be discussion of different programs. If you enjoy math competitions you could see if there is an ARML team in your area.
If you are not interested in early college, have you considered doing something completely different. You could look at a year study abroad, particularly if you are interested in languages. It sounds like you have plenty of credits to get your HS degree thru your homeschooling. You don’t need to rush to college take some time to really explore an interest.
You could also apply to colleges next year and then hold off a year on attending.