What a horrible experience for you and one I can truly relate to. When I was staying at Taviuni in Fiji, the trip over was bad enough on an ATR 42-500 seating 44 passengers. Flying back to Nadi from Taviuni, I watched a couple of planes come and go wondering if they were my flight. Next thing that flies in is a tiny plane reminding me of a model aircraft. The realization that was my ride back to Nadi made breathing difficult.
I turned around and began to walk away from the building but husband was way too quick and grabbed my arm. He practically frog-marched me on the plane, stuffed me in the door and proceeded to strap me in. I was frozen with fear and he had to keep reminding me to breathe. Our pilot was female and she really was lovely with me and very reassuring. Unfortunately I could only see her lips move. I think the fear made me deaf. Anyway I made it without totally flipping out and when we landed and it was ok to exit the plane my husband said I looked like a cork popping out of a champagne bottle.
It was the most horrible hour of my life and I was imagining my death the whole way. Funny thing was, when I got on the much bigger plane to fly home, it didn't bother me at all. Stick with it and I hope it passes.

The cause of my hour of hell.