WHAT IS HAPPENING TO ME!?!?!

ok, so, I'm mad at my good friend because she's being two-faced by saying to me that she DOESN'T like this guy I hats, and then, the Далее thing I know she's dating him!!! And today in first hour, I felt like...like a hole of darkness или something was opening inside of my chest and closing up my throught. I FELT it. PHYSICALLY. I SWEAR. Was it real hatred? или am I sick или something? Please help, it would mean the world to me as of right now.