All weapon choices can be made to work. 2H is actually one of the strongest choices in PvP since it has:

• A frontal cone attack that provides a substantial, spammable damage shield (cleave -> brawler)
• A strong, high damage gap closer (critical charge -> critical rush)
• A high damage CC (uppercut -> wrecking blow)
• An execute ability with side benefits (reverse slash -> executioner)
• A self buff that also provides the only easily achievable stamina based self heal (momentum -> rally)

You could actually fill your 2H bar with only these abilities and make worse choices for a build (I know, not a good idea, but you could!).

You get rekt in PvP not because of your weapon choice but because you are new (believe me, it takes a long time to train the necessary reactions to survive no matter what class/build you are using), you are underleveled for veteran campaigns (in essence you are starting level and all others are max level) and you are probably still undergeared, since it does not make sense to spend half a million gold (PC prices) on equipment and upgrade materials at Vet Rank 1.

As for the second part of your question, that depends on what you want to achieve. If you have no ranged class abilities and would like to have ranged options, go for bow as backup. If you want better AoE synergies, go dual wield as backup. If you want survival increase, go 1H&S as backup. I would suggest testing them and only finally decide after you learned the ropes and your personal playstyle.

EDIT: I just assumed that you are actually "configured" for 2H damage dealing, in the sense that your attribute/enchants increase stamina and health, use class abilities stamina morphs wherever possible and prioritize weapon damage and then weapon crit (in this order) in your gear choices.

You can use S&B for defensive posture and decreased block cost, or use a bow and snipe people from stealth.

The most important thing for a stamina DK is to keep GDB and rally up all the time, buff your weapon attacks and dodge them frags.

I think there are quite good stamina DK builds so you could lookup some videos to learn their play style.

Alright, now I'm using wrecking blow, rally, critical rush, gdb, and dragonfire scales with take flight ultimate

I am using 2h and a bow as backup, just hit vet rank 1 but my question is, How should my attributes be looking?

Right now I have everything into Health.