Sorry to hear about your kid's struggles - anxiety in middle school is so tough. I researched this extensively last year and found some solid guidance
https://www.gigwise.com/best-online-middle-schools/ that helped narrow things down. Look for accredited programs first and foremost. Check if they offer live classes with real teachers (not just recorded videos), have strong student support systems, and provide opportunities for socialization like virtual clubs or field trips. Also important: ask about the student-teacher ratio and how they handle questions. Good programs will let you trial a week or two before committing fully.