i have experienced sleep paralysis many times....sometimes at close intervals...sometimes months and months in between.
unfortunately, they are usually frightening experiences. as was mentioned in another thread about sp...i usually would pray or use the name of Jesus to break the sp.
this will usually work because i feel that i am usually in a vulnerable emotional or psychological state when i have the sp...and feel that there is an evil presence during them.
i have experienced the buzzing in the head, the feeling that something was holding me down, that there was a presence in the room...kind of a shadowy figure, that there was movement in the bed..one time like something was trying to lift me off the bed.
regardless i have always felt that if i did not break the sp that something horrible would happen to me.