Serious Question

Ok, so I go on vacation to San Francisco/Santa Cruz/Napa Valley and two days before our return to the D I woke up with a raw sore throat. That night the back of my throat started to tickle and sure enough I woke up the next day with a cough. Sunday came and my voice started to go froggy, I spent Monday and Tuesday exhausted from nights of sleepless coughing and days of explaining to our customers, vendors, etc... why I sounded like a man. I finally got a good night of sleep on Tuesday and felt my voice loosening up yesterday along with the phlegm in my chest only to start sneezing and blowing my nose while having to do the suck in breath thing between bites of food at dinner last night. Today I've sneezed several times; on my shoes, on my hands, on the ground, on my desk and have covered nearly ever surface in snot. Now I realize there's probably no one left reading right now but I have a serious question to ask. Where does the snot come from and have I always had this much in my head? Is it becuase of some bacteria or virus that it's just now making its cry for freedom through my throat and nose?? I thought I was on the upswing of this thing and now I'm starting to wonder...figures I would go alllll winter long without even a touch of the flu or a cold and as soon as summer and my vacation hits, BAM, onslaught of wheezing, sore throat, coughing and runny nose! It couldn't be the fact that I was totally off my mostly healthy routine while in Northern Cali, eating every unhealthy thing I came across and washing it down with several forms of alcohol while sleeping restlessly in 4 different hotel beds for 6 nights, not to mention slacking on any form of exercise....nah, couldn't be that.