I have severe hives, terrible headache, left side chest pain and fatique?

Severe hives: Severity is subjective - but if your hives are really bad - go to an ER (at least to a doctor) to be sure they don't become life-threatening. These mysterious allergic reactions can affect you internally too and if they swell up in your bronchial tubes, suffocation can result. It's why epi-pens are Rx'd for chronic hives patients. Get treatment and prophylactic protection if needed. Take care.

And you want to know: What to do? In this case there is no question. Hospital ER evaluation. Sounds like a severe allergic reaction to me, but this is only a guess based on a constellation of symptoms. So since you have chest pain send severe headache with fatigue, I suggest you get seen today in an ER and follow up with your primary MD as advised.