HELP my entire left eye is swollen shut?!?

The first thing I would try is an anti-histamine pill such as benadryl in case it's an allergic reaction. I had this happen to me and it was a reaction that got better with benadryl. You could also try eye drops to sooth the eye. If it doesn't get better within a day (or if it gets a lot worse), I would definitely get it checked out. Hope it gets better soon! Good luck!