Its a spiritual attack. It happened to me allot. The easiest way out that always works for me is to say the lords prayer in your mind. Everytime i get to the part that says diliver us from evil my entire body always shakes like crazy and when i get to the end of the prayer i snap out of it. Last time this happened was last week and i was so exhausted and didnt feel like saying the prayer in my mind so i said Oh Jesus please help me and as soon as i said that i was set lose from that state. Ive seem many strange things in that state. The doctor's will tell you one thing but i cant deny that its a spiritual thing. Jesus really is real and those powers that come upon you and hold you down have to let you go when you ask God for help. You have to repent of your sins though or God wont hear your prayer. It is mind blowing to me tgat even my thoughts God responds to. Thats definitely mind blowing. You should try this it really is a life changer and increases your faith.
12 For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.
9 Wherefore God also hath highly exalted him, and given him a name which is above every name:
10 That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth;
11 And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.
31 Now we know that God heareth not sinners: but if any man be a worshipper of God, and doeth his will, him he heareth.