I assume this was the crowd you are talking about. Anyway, you done well to stay strong. I'll tell you one thing i've been on as AR in some games with hostile crowds before, and it doesn't make things easy. If you make the calls as you see them, and are confident about them, then it doesn't matter who makes comment. There will be times when you doubt yourself, but you can't dwell on these because it will just lead to a lack of concentration. You have also got to zone out of what is being shouted by the crowd and concentrate on your job. Let them bark out what they want, because in my experience, they haven't got a clue or their opinions are obscenely biased. So its in one ear and out the other for me. If the players are involved regarding dissent then you have powers to advise the referee and he will take the appropriate action if required. But letting the crowd get to you, as well as the players I may add, will only affect your performance. Stay strong, be confident, don't let dubious decisions play on your mind, and concentrate on what you have to do.