Guild Wars 2

I have Vanilla, HOT and the Living world season 2. I just reached level 80, I feel incredibly underpowered for the Living World and I’m not sure what to do.

You’ll want to have all Exotic level gear (or higher), especially for the HoT maps where mobs can really pack a punch. Make sure the gear slots are also filled too as that adds a lot of power. Make sure your gear/runes/sigils go well with the character build you are using. Other than that, practice.

depends on what class are you, vanilla is fine but HoT some mobs hit like a truck even with heavy ascended gears you can skill got killed by a single mob if careless in battle.

Yes like Boysenberry said practice is a key to survive in HoT map, and gears stats i recommend Marauder with Power Precision Vital Ferocity and zerkder trinkets/weapons or mix between zerker trinkets with some defensive stat trinkets if you feels like your hp is too low ( seriously you might get 1 shot in HoT )

Exotic doing just fine in HoT, try to gear up, learn your class, you can buy gear via trade post or badges of honor vendor or by crafting and Marauder kinda expensive to craft