Yes it gets alot better once you pump out that haste close to 21%+ before that… Youre basically trying to get out a cast that will be delayed 4 times from a mobs melee attacks wasting your leveling time even further.
Its hard, you dont have mobility and you dont have a way to clear out roots/snares/immobilize. That itself will kill you many times over there.
We have been whining about priest mobility for a long time here in the forums and because priests are the only spec that cant clear roots/snares without using their 2min CD or with absolutely no way for holy/disc. But as it seems blizzard is ignoring us and want us to play priest like its WoD DK that had only deaths advance back then.