What attack can this be?

Ok so right now i laid in my bed and then all of a suden i couldn't move but i was awake. I tried movin but only my feet would move. I started breathing heavily and then i felt like if a grenadeexploded in da room and my sight went black and then came bak really quick. I then moved and stood up. No pain or nothing. This has happened a couple of times before. Bhr not sure..what can this be?