I don't know if anything will work for your child in particular, as my kids are still younger much than your son. But anxiety runs in my family. Things that seem to work:
getting enough sleep
lots of exercise
some type of cognitive therapy (learning coping mechanisms, stopping negative talk etc.)
my brother says heavy work (lifting, shoveling, etc.) helps him reduce anxiety as well as meditating
gardening (there is some study that says bacteria(?) in the soil actually helps counteract depression/anxiety
Controlling blood sugar spikes /dips etc.
having something you are involved in that is meaningful
I can't help you with the schedule, but you can try things and change as needed.
