Guild Wars 2!

[Shadow]

I usually just use the shortbow. Most of the times I don't have any trouble, it's just the story quests where even if I don't attack at all the enemy will just ignore my bear and try to kill me instead. So I don't know if the weapon I'm using really has anything to do with it.

Though I'm level 19 now and have crafted a level 20 shortbow and longbow so I could switch from shortbow to longbow if I needed to.

For shortbow, I suggest initiating with crippling shot (4). It will slow the target down, allowing your pet to get to him before he gets to you. It also makes your pet's next three attacks bleed, which should pull the aggro.

This is probably not what you'll hear from many people, but if you're having trouble I really suggest sword/dagger as your secondary, particularly when in story missions.
It has a veritable crapload of dodges/evasion/mobility, and it also has a couple of cripples.
--(1)auto-chain has a cripple on the second strike and a leap on the third
--(2)chain has an evade on the first strike (8 sec cd) and a leap & a cripple on the second
--(3) is an evade (15 sec cd)
--(4) is an evade (10 sec cd)
--(5) is a cripple
It takes some time to get used to how this s/d set works, but once you get the hang of it, it's amazingly survivable. Don't be afraid to mix it up in melee if enemies close in on you. Three free evades (all on short cooldowns, plus your dodges) and two cripples on five skills is often better than kiting (or can set up the kiting by getting behind and then crippling so you can get away and switch to your bow).