What Causes Sudden Fainting On A Recurring Basis?

I have been experiencing unusual near fainting episodes, as if i was consciously fainting. My face will suddenly feel like its going to fall off of my face, my head nearly drops down, my body suddenly feels limp and its as though I m going to pass out. I also have spells during conversations, its nearly impossible to finish a thought without feeling as if my face was going to fall off and it makes speaking near impossible and my mouth gets dry as if my tung was going to stick to the top or sides of my mouth, literally, my tung feels dry to the touch and a bit swollen.