One: welcome to the ranks of healers...

Two: my SCH is only to level 60...and i struggled a lot. A friend that's actually done SCH to 70 finds it very hard for large pulls, but he does pull through. i'm going to shoot him this forum thread so he can maybe give additional advice to what has already been said here.

E4E is essential for the SCH kit (as emergency tactics - 60 skill i believe) makes use of it (why they took it from SCH in the first place is beyond me...)

However...the big thing is: if it's too much, let the tank know (as Connor said); if a tank can't understand that you're struggling, there's an issue. I've done this on WHM (my main and Main Heals) and there are a lot of tanks that will just...pull as much as they can. So...if you Can't handle it, you need to let them know.