I agree - the focus should be on his health. You can navigate the rest later.
We actually had to move my younger son to a charter for part of Sr year due to persistent migraines. The break worked and he has largely eliminated the migraines - and actually just graduated from Ft Lewis, an CO public college. Our HS counselor heIped ID the classes he still needed to get into a CSU. He held himself accountable for the on-line work.
One thing we learned, OOS publics (I connected with UNR, Boise State, CO State and Ft Lewis to confirm he’d meet their admit requirements. They are much more flexible on their required classes than Cal States and UCs. Do your own research but they were all really responsive and supportive for us. Contact any place he’s applied and ask their guidance before making changes so you know which doors you are closing before its too late.
I have a close friend whose daughter used the same charter to graduate HS in 3 years and is now a sophomore at U of Arkansas - so, you don’t need to do the traditional 4 year cycle to complete the HS requirements.
If you are in CA, there local charter school that can help you navigate this difficult time.
If you think he can handle a traditional college experience but might be a little short on the A-G list, look at WUE schools - a group of Western publics that offer discounts for CA residents.
Here’s a link.
https://www.wiche.edu/tuition-savings/wue/wue-savings-finder/
If that’s not for him, your local CC is always a viable option to continue education in a more supportive environment.
Good luck