To be fair, normal mode AK is balanced to be done in ilvl 50-60 gear.
Nowadays even just doing your jobquests you get gear that puts you way beyond the requirements for said dungeon,
so large pulls are the norm since it is really hard to die there, even with the ilvl sync set to "only" 110.
Personally, I find AK fun exactly because of the giant pulls that are possible there

(later dungeons usually have lots and lots of walls that stop progress until every tiny group of monsters got beaten by themselves because SE hates speedruns)
But I can see how that would be overwhelming for a healer who is new to the dungeon.
Don't be frustrated, try to think of how enjoyable it is to actually be forced to focus on healing for once and do everything in your power to keep the group alive ^-^