I am going to echo what a lot of the others have said here. mana will be tight for you till you have regen and then shroud. best advice i can give you is try to heal with cure and use cure 2 free cast procs as much as you can. It will get better trust me. once you have regen, better stoneskin and shroud you are the best healer in game and most fights should never give you much to worry about mana wise assuming you don't spam cure 2