The trick with SGE is not being afraid of oGCDs. More than any other healer, SGE wants to use oGCDs all the time. All the healers, when played optimally, use oGCDs more than GCDs, but SGE's GCD kit is narrow and, when you're starting out, somewhat shockingly weak. It's roughly the same strength as other healers, but it's losing out on SCH's Embrace when using it (no Kardia when GCD healing) and it doesn't have the stronger GCD heals that WHM and AST do.

SGE is very intuitive for people that have been playing FFXIV healers for a while, particularly for SCH mains, but it's not very intuitive for new healers that have not and are thinking in terms of "Where's my Cure 2?" or that haven't learned how powerful, cheap, and high uptime abilities like Physis 2 can be, or things like Soteria or Krasis.

Learn to use those oGCDs and keep the Addersgall gauge filling, slipping things like Physis 2 into your rotation during pulls that need it, using Kerochole and Taurochole (NOT at the same time, they do not stack) to keep the tank in a near-permanent 10% damage reduction state, and using Panhamia (even just on the tank) and Hamia, alternating, for the two sets of wall-to-walls you do between each boss. And unlike SCH, you have no reason to not spend AG on heals, and in fact you need to to keep your MP regen going.