Am I totally screwed?

Okayyy soo I skipped ahead to the crumbling farum azula area before ever exploring lyndell or the land of giants (snowy area). I did this because i wanted to do every questline in my first run-through so my NG+ could just be chill. So i was exploring and i ended up killing malekith…..which then burns the shit out of my favourite tree. And now lyndell is ashes and im trying to figure out how much i just screwed myself in terms of quests and also bosses/areas.

Can anyone give me a general estimate on if i missed any major bosses/questlines? From what i can tell i think i screwed the dungeater quest, and maybe the boss at the end of lyndell? I just dont wanna miss any good items/gear before i start NG+. Thanks!

P.S I havent killed rykard yet because i know he gets rid of some quests.

TLDR: i skipped lyndell and land of giants and started the burning of the tree accidentally. What did i miss in terms of bosses and quests?