Starting healing with AST... Did I bite off too much?

[GeekMatt]

What Zari said. WHM is a great starter healer if you're looking to ease into it, but if you like AST I'd just stick with AST. SCH isn't easier, IMO, it's very different from the other two healers. What is it you're finding difficult about AST? Healing large pulls? That can be rough on any healer if the DPS is really slow, but AST has a solid toolkit for keeping the party alive.

Run dungeons in Diurnal and keep up Aspeced Benefic as much as you can (as long as it falls off before the next pull), and if it's stil tough on you, you can throw up a Aspected Helios for additional regen on the tank, and lastly to make things temporarily easier, Synestry before Aspected Benefic/Helios to increase their potency as well as the potency of your single target heal. (I'll often refresh Aspected Benefic as Synestry reaches it's last second). If your tanks struggles and your party's taking damage use LightSpeed to keep on top of everyone quickly while saving you some MP, and if you're not too worried about your tanks aggro management, use it early on as you spam Benefic/Benefic II just to save you some MP. Also on larger pulls (or any situation where I'm confident I'll be draining a lot of MP) I'll use Luminiferous Aether the second there's a visible gap in my MP bar that I know won't fix itself naturally (So after about 2-3 Benefic IIs or Gravities I think?). At 60 you gain the ability to instantly stun everything which you can use to buy yourself some time in a pinch.

Lastly, don't DPS unless you're confident your tank will live.