Lot's of belittling went on during the course of my 6-7 hour long oral only to be failed at the end. Needless to say my confidence is very low right now.
If you had a 6+ hour oral for any rating in any type of equipment don't ever get near the jack*ss that did that ever again. That's an absurdity in the extreme, and I mean that!
No oral should be longer that a couple of hours and that's a lot. If he can't figure out what you know or don't know in that amount of time, then HE/SHE doesn't know what h/she's doing and is unfit to be an examiner. Seriously.
Check around and find a decent examiner. I understand your feelings but don't let that idiot intimidate you and cause you to lose confidence in yourself. If you know the material and get a fair examiner you'll get your rating.
Best wishes.