Allergic reaction to DayQuil?

So i've been sick all week and done nothing about it, so this morning I decide to take some dayquil right when I wake up to help get me going. Anyways 20 minutes later I'm sitting here and my eyes are swollen so bad it looks like I got in a fight with a Gorilla then smoked a blunt with him afterwords. Anyone else ever have a bad reaction? I used to take this shit all the time and never felt anything wrong.