Sorry to hear you've got the flu bug! Hot showers, eucalyptus body wash by Burt's Bees, lots of fluids and rest are what got me through it in Nov. This was prior to my 2nd concussion, so I think you should give yourself extra time to recover. Mine lasted about 2 weeks but I was fatigued for quite some time afterwards.
How is your son doing? Sending healing hugs to you both!