What about the people you see hypnotised on stage or TV shows? In these shows participants are apparently made to believe or do ridiculous things. However, stage hypnosis requires willing volunteers. These people obviously have a desire to perform, or they wouldn't volunteer to go on stage in the first place. In volunteering themselves they are implicitly giving permission to the hypnotist to 'make' them perform.

Will I be able to wake up?
When hypnotised you are not asleep or unconscious. You will normally have your eyes closed, but you can still hear, feel, and speak. Indeed, your concentration and awareness actually become heightened. Even if something happened to the therapist you would return to normal awareness in your own time, comfortably and easily.

Will I remember what happened during hypnosis?
It would be unrealistic to say that you will remember everything. You will remember some things but not all. This is the way memory normally works. For example, when you listen to a speech or talk you don't remember everything that has been said.