They are obviously impressed with your skills and feel as though you are the best one for the job. I understand the stress you are under...it would be hard for most people, not just someone with AvPD...but attempt to look at it from their point of view. You are talented and they feel as though you are best suited to represent them. When you get stressed remember that. This could potentially lead to better things in the future as well.

Do some research in to Indian culture...common things to say and ways to act. Write them down and put them in your pocket. When you feel lost and that you just want to hide in the shadows, pull it out, read it, and try one or two of them. Remind yourself constantly that you are of value to the company and that's why you were chosen...not as a punishment as it seems. Hang in there!