Just keep being resourceful and you’ll improve. The game has changed quite a lot and there’s alot of tools you can use to increase your DPS. I’d recommend watching a youtube video on how to optimize your gear on Raidbots, get some hunter weakauras, and really pay attention to the little things in the guides you are reading, Covenants, Conduits, Enchants, Stat prio, and a bunch of other stuff matters a lot especially when comparing yourself to a player who is doing all the little things.
If you have a hunter in your group who is out performing you reach out to him and ask for some help. Ask him what he is simming for and compare it to yourself. Don’t get discouraged just remain resourceful and you’ll 100% do better.