Hi; don't worry about the Endoscopy- I've had TONS of them, and it is the easiest test to go through! I take off earrings, necklaces and my watch-easier to leave them at home. I wear pants and a comfortable top. Sometimes they have you take off the top and wear a hospital gown, sometimes they don't. You will have an IV, which is how they will make you loopy for the test. You won't really be 'out' in the sense of surgery. The meds they use normally include Versed, which keeps you from remembering. This last go-round I had was an endoscopy and a colonoscopy, and they woke me up for a few minutes to look at some pieces the DR was taking for biopsy in my colon...then they put me back under. It's just that easy.
You'll wake up really quickly, and will be groggy that afternoon, but aside from a scratchy throat, there is no pain at all. Be glad you are having it done...it is the best way to get accurate diagnosis, because the doctor is really looking at you. The doctor will probably take several biopsies, so don't worry about that-it's under the microscope that they learn the most.
You are going to do great!!!