What does your diet look like?
How much sleep are you getting nightly?
How much stress/ hours are you putting in at work?
Are you supplementing with an antioxidant/ multivitamin.

Your body is pretty good at letting you know what's going on with it. When I'm training hard, every 5 weeks or so I will take a week to deload. I'll drop the weights in the gym, sleep more, and keep eating the same high level of calories. More sleep and more food can do wonders for pulling you out of the hole. So can vitamins, especially since overtraining takes a hell of a whack at your immune system, and getting sick on top of overtraining can really do a long term number on your body.