Why am I feeling faint?

Ok so I'm in my early 20's healthy female. Just yesterday I got a realy bad headache almost like a fever headache it realy hurt. Then my throat and tongue started swelling up it was hard to breath. I feel faint and everytime I staind up I get real dizzy like I might faint and it gets black and I have to sit down . My heart is beating kinda fast. What could have caused this? I have no allergies. Only thing I can thing of is I lost a lot of weight recently but that was from eating right and excersize.