It's tough to shake if you're already showing symptoms but here are two things that WILL help at least:
2. Water - 10-12 glasses a day
A multi-vitamin will probably help more than Airborne or ColeEeze.
Definitely don't smoke, and don't drink... much. A few beers may do more harm than good but downing a bottle of jack might help a lot:-b
If you're a battery, you're either working or you're dead....