what is hypnosis really?!

First the hypnotist relaxes the subject. Then the hypnotists talks to the subject giving them suggestions. It is important for the subject to be in a relaxed state. If you pay attention to how the hypnotist is talking you will notice their tone of voice and speaking patterns are different. So the main differences are that the subject is relaxed and the hypnotist does not talk in the normal way.

They try to get the subject into a more receptive state then they give the subject suggestions. The subject can ignore the suggestions if they want. The hypnotist is guiding the subject not controlling them. It is a bit like acting class. The hypnotist sets the scene and the subject plays the part like the scene is real.

http://www.mikes-space.com/hypnosis.htm

Originally it was made up by a guy names Joe Mesmer (thus the term Mesmerize). It is basically fake. There is no way to take control of someones mind. It has no basis in reality.

It is a kind of mental paralisation(controlling once mind temporarily).

you should go to doctors immediately.