Dealing with demanding people is hard enough, but now let's up the ante and respond to someone who is really critical and insulting. Imagine you're on a big project and one of your peers on the project says:
"You have really screwed up on this project. All the stuff you've given us is wrong and we're going to have to re-do it. You are nothing but a parasite."
Whoa. So your first reaction is to say "I'm not a parasite!", but that would be wrong. Yes, it's a mean thing to say and it's not true, but if you get defensive and start arguing, the confrontation is going to escalate quickly. And believe me, you are never going to convince her that you aren't a parasite in this conversation. You have to swallow hard, ignore the insult and saying something like:
(AGREE) "I did make some mistakes in the material I sent you."
(EMPATHIZE) "It's frustrating to everyone when a project is delayed like this."
(INQUIRE) "I thought I was doing the work the way you wanted. What should I have done differently? What do you do when things go badly?"
You have to manage your emotion if you want to get past the confrontation and on to some kind of resolution. It's not an easy thing to do, but it's the only way.