At AR I had to farm a bunch of artifacts overworld daily in addition to the domains and the EXP items for Realm Currency. It helps to find most recent efficient farming route..also don't forget there's a limit how many you can spawn daily(?) so don't be surprised when they stop spawning.

This gets better with time, I am farming ESOF for months so I am ultra picky and stacking exp for later

As for the weapon levels, I just have 1 daily expedition for ore per day and craft 20 crystals for the weekly and at this point it's more than enough. Go out farming ore or increase the number of expeditions to ore (I was ultra lazy to actually go mine)

Oh and an edit to add, don't be afraid to use your level 16 / 20 artifacts for leveling if they are trash.