1. You can join the non veteran campaign (Blackwater Blade). There everyone has about the same stats and the fights last longer has people have more health and less weapon / spell damage. It will still be hard in the beginning, but with each skill and passive you get, you will become more powerful.
2. If your enemy has some kind of whirlwind around his feet he will be immune to hard cc (snare and root still works). There are 3 ways to get temporary cc immunity: A potion, the heavy armour skill and just after you have been cced.
3. As long as you don't deactivate battle levels which set your stats on par with higher lvl players or reach veteran ranks your gear only matters to a small extent and your attribute points will be ignored. I'd recommend just to try out if you want to be more tanky and block a lot of the damage or if you want to win by killing your enemy before he can harm you. Both is possible on a dk.

It's a learning curve, often a painful one.

It will take some time to find the combinations/gear/playstyle that works for you. Doing the PvE content in the game (learning skills/synergies/group coordination) do help regardless of what PvP only types will tell you.

It's also a way to learn/try different skills and combinations in a more forgiving environment.

The short version is, "Yes, it eventually gets better."

It does take time, a whole lotta dying, and patience.

I'd go with support at first - don't expect to be able to walk to the front lines against VR14's that do this all day long and not get your butt handed to you.

Take it in spurts - if you start getting irritated at it, come back another time. Helps keep from getting completely burned out on it.

Once you do start to see it 'click' though, you'll be hooked.

(And for the record, even after you are a VR14, fully decked out badass, you'lll still get your butt handed to you from time to time - it's just the nature of the beast!)

Good luck!