So scared i have oral cancer, i'm 18, throat hurts, tonsils hurt, back of tongue hurts, post nasal drip, chest hurts to breathe, throats swollen. help?

Don't be scared: The symptoms you describe can be attributed to many so many other ailments, including the common cold. The chances of you having oral cancer are almost nil... I would strongly suggest, however, that you see your physician to treat whatever ails you. All the best...

Seasonal flu: is very common viral infection. Usually the condition resolves on its own with home care. Drink water and get a good rest. NSAIDs (e.g. Aleve, Advil) or Tylenol (acetaminophen) are also recommended every 6 hours. If concerned, see your PCP for examination.