Really random sickness contracted from a coworker

I contracted this really weird cold from a coworker during this past week when we had a lot of deals in the pipeline.  My coworker came to the office when he probably should have stayed home and we worked on several deals throughout the week, hence I was in close proximity to him.

The week after I started feeling under the weather but because of the urgency of the deals, I forced myself to power through the week but ended up having to take Friday off to rest.  The symptoms were something that I have never experienced so hopefully someone (anyone) who reads this has an idea, that would be greatly appreciated.

Symptoms listed in chronological order:

1. Extremely sore throat (but very little/no coughing)
2. Light fever
3. Congestion in the evening when sleeping
4. Loose bowels / stomach problems / diarrhea
5. Congestion during the day
6. Sneezing / coughing

This all happened within a 5-day period.  What the hell do I have?

I also have this really random (but possibly related) question as well.  When I fall asleep, the nostril on the side I'm laying on (so right nostril if I'm laying on the right side of my body) will get congested and stuffy throughout the night.  This will cause me to toss and turn as I'm trying to regain "passage" through that nostril. When I turn to the left side of my body, my left nostril gets congested while my right eventually clears up. 

What is the cause of that and what is the remedy?