You shouldn't be stressed at all and the guy saying "your main function is healing and you should focus on that" is absolutely right.
You are a healer, not a dps. (de don't even count healer dps to calculate dps check. Altough I have high doubt whether or not this is true for v4/8 ans super savage.
Now before anything, since ff14 dmg c
Mostly comes into the form of burst (avoidable or not).
It means that the more you know how these burst come, the better ans faster you can heal through those (leaving you more free time).
Then come tank and dps. The better à tank will mitigate, the less heal he'll required (so more free time) and the less dps die and take useless dmg, the less spot heal will be needed.
In the end, once all the avoidable dmg is avoided, tank mitigate properly and you perfectly optimise your cd, you'll realise you have A LOT of free time.
Now at this point, the question is "should you spend 70% of the fight doing nothing?"
If you feel like "yes" then don't dps
If you feel like "no" then dps.
Finally, there's something funny happening when you don't need to heal.
If you don't need to heal, it most likely means no one is failing or dying.
If no one is failing or dying
, then most likely the dps are competent enough to meet the dps check.
If dps are competent enough, the in fact your dps contributions is useless because the boss will die anyway.
The sad truth is, the more dps fail and die, the more your dps will be valuable.
I personally dps whenevr I can but I absolutely do not feel pressured. If we meet the enrage on anyrhing that is not v4-v8 or super savage, it is surely not because I didnt d enough dmg.
Dps is simply optimisation, it's candy it's a bonus.
The fact that you ask this suggest you havent even set foot into savage. If your group (for baking for ex) needs your dps, well your group is just terrible because theres no way an average group should need heal dps to complete the fight.
(skipping phase is a different story)