Well I see that you aren’t at 120 yet, so I would suggest using Incanters Flow and Living Bomb for talents while leveling or dungeoning.
Its really hard to say what the issue is when you’re not at 120. But if you are struggling on dungeon bosses, most of your damage will come from a combustion rotation.
For me its Fireball till Crit(For heating up) > Fire Blast > Rune of Power (If you have incanters you dont need that) > Meteor > Combustion > Pyroblast > FireBlast > PyroBlast > Scorch > Scorch > Pyroblast(Instant) > Pyroblast(Instant) > Fireblast > Pyroblast.
That requires a little bit of haste to work properly but I’m not sure the specific amount, the double pyroblast sounds weird but the best mage in my mind Imfiredup, found that little trick, and I found about it myself.
Basically if you hit scorch, then cast the second scorch, then spam the instant pyro ability, you’ll be able to cast the Pyroblast(Instant) before the Scorch hits the boss, so at that moment you’ll have that Pyroblast hitting the boss, and you’ll instantly be able to cast another one, and if you have enough haste, you should have enough time to get another Fireblast and pyro off right as Combustion ends.