I know I need new equipment with my DK, she’s currently iLevel 347 but she feels like she’s hitting everything with a feather duster - even open world trash that other toons have no issue.
She doesn’t feel like she’s about to die, it just takes an age to kill stuff.
Unholy does give that feeling of weakness because it doesn’t come with an ability of “you point at it, it gets smashed instantly” like most melee do.
And if you didn’t time your stacks perfectly for a target to die, you’re stuck toughing it out than risk spending 2 runes where festering wounds get wasted as well.
I’d say it’s more akin to a affliction warlock, but you can’t turn away to let your plague do the work to go next target, you always need to be hitting it with auto attack to maximize damage.
Gear does play a role in how well you deal damage, to an extend.
The other part is knowing what to do.
If someone with lower ilvl than you who is also an Unholy DK, Does more damage than you. That simply means he is better at the class, and knows how the does rotation works.
A class isn’t weak, when you are 50 ilvls behind the average raiders ilvl. And seem to hit your enemies with a pillow.
I suggest looking up some icyveins guide for the basics, and getting some more gear to improve.