No its not normal, they were being an ass; there's really no excuse for their behavior. Chances are, you could have handled the extras they pulled, but thats not really the point. What they should have done is asked you to pull more instead of pulling for you. The healer should have encouraged you to pull more if the healer thought they could keep you up through it. But ultimately, its on you to pull to what you're comfortable pulling. If you aren't comfortable with it, dont do it.
Of course, as another said, you only learn by doing it. Go ahead and pull small for now, but then when you get a party with a couple decent aoe classes, pull a little bigger and see how it goes. Keep practicing and eventually you'll get up to where you pull all the things!
