Surrounded by Cold and Flu

So like two weeks ago I went out with my bf to a company party and one of his boss was sick, coughing, snot, all that good stuff, a few days later my bf got the same thing (still has it), so did his other Co - workers and me? I got really hot one night and had diarrhea all night; so the next day I drank some powerade and ate everything salty and that was that. I don't think I've ever gotten the flu before, but then again I don't know the difference between a cold and the flu... bf is still coughing and stuffy and I feel fine so far... so I'm wondering if that bout of diarrhea was it and now I have the antibodies for it... or am I going to get sick too?

Anyone knows how this all works? He's been coughing in my face for days (gross)

Also what's your favorite medicine/ remedy for colds/ flu