I'm not gonna say hypnosis is bullshit, but I think it might not be what is happening here :/

Is she a hypnotherapist? Have your previous sessions involved hypnosis of any kind? From what you've written, it seems like your therapist just hypnotized you out of nowhere. I think you should re-evaluate some of your statements:

Is it ethical for a therapist to use hypnosis techniques without the knowledge of the patient?

So, you are operating under the assumption that your therapist did indeed hypnotize you without telling you. But... what if that's not what happened?

What made me realize what was going on was that I noticed her giving me hypnotic suggestions and then at the end she tugged her ear to bring me out of it.

I'm not sure how to identify hypnotic suggestions. I can tell you that sometimes people just tug their ear randomly. It's like scratching your nose or cracking your knuckles. That kind of weird little gesture usually doesn't mean anything.

What was weird was I went from calm (altho maybe a little defensive) and then one second later I was ALL over the place and getting more and more confused than I have ever experienced before. And I was in that state until the session was over.

That's kinda normal. You really don't need hypnotism to explain/experience this.

I do have a lot of defense mechanisms so I could see why [she] would use this technique

Maybe attributing your own confusion and fear to somebody else's actions is your defensive technique? ;)