If you equip the field commander set and casting accessories you can actually do solid damage at the cost of a load of secondary stats and healing potency. It can be fun to play as a "support" though as long as you have people doing the bulk of the healing.

That said, get used to not having a proper "group" in pvp. You will get matches with all tanks or all dps who stubbornly won't switch. It's just part of the game and a side effect of having no party comp requirement for queueing. Just get through it and hope for better luck next time.