Actually it was probably your lack of heals, not your lack of a tank, that did you in on Hammer Station, since at that level the tanks are just not that tank-y yet.
Quoted for truth. HS is super easy for 3 DPS and one DPS that has a healing skill, all level 17. Use your CC abilities. The last fight might give you a little trouble without someone with some tanking skills, but it is by no means impossible without a tank.
OP - This is not GW2, it will never be GW2. However, I like the mentality behind GW2 as well. You need to understand that these are different games, with different systems, and they will never be the same.