He´s in his 6th week, how come he tolerated the sust so long and now gets sust flu? Seems unlikely to me.
AAS supress your immune system a bit (exception: Deca) so you might have caught an infection. Go to a doc if it doesn´t get better, antibiotics might help. If it´s a virus, you´re fucked and better stay in bed until your body fights it off.
What kind of sust are you using?