What makes this game fun is you can do whatever role you like! If it makes you feel any better, I am THE WORST at DPS. My numbers are terrible, I never move out of AoE, all I do is stare at my tool bar (and still suck).

I always prefer to heal or tank any content. Not sure why I can handle those roles and not DPS. But a good DPS supports the party in its own way, by ending fights quicker and utilizing their own support skills (mantra, litany, vulnerable rebuffs) so I don't think you should feel bad about it at all! Having good DPS makes all the roles have an easier time.