First thing’s first, for the next time it’d be great if you enabled advanced combat logging (found in systems – network). Since it wasn’t for those kills I can’t check things like talent choices, gear, mana usage etc.
– You are casting healing surges more than healing waves which will drain your mana very fast. Unless you have the legendary bracers I’d only use healing surges if you need it to save someone from dying, otherwise healing wave is preferred since it heals at base for the same amount and when used with tidal waves charges (as it should be) it is just as fast.
Out of curiosity, is there a reason you single target heal only? You’re enchanted and gemmed for crit which favours a chain heal centric build and yet you cast very few chain heals. You might find it useful to read through the talent and stat priority sections found in the legion hub at the top of the page.
I’d also suggest swapping your neck enchant to Mark of the Trained Soldier. The Ancient Priestess one is not very useful to us resto shamans.