Then your personality or your ADHD might not work with being a Healer. If your low on mana and the party wipes because you been DPSing the entire time its not the Tanks or DPSs fault. Your job is to heal put Medica II up and if you know your going to throw out one or two Holy Bombs or Hits make sure your tank also has regain on. The problem with the Jobs in this game they made the cool jobs Tanks. So there are a lot of people who roll the wrong job for the wrong reasons. In your case you rolled because of Glam?
As a White Mage you have three DPS skills. One a regular attack, the 2nd is a overtime attack skill which is easy to put on, and then you have a third spamming Holy Spell.
What some DPS Healers don't understand if you only start healing once your tank is at 15% chances are that tank is stressed. If he gets hit with Paralysis and you don't Esuna it because you're to busy DPSing if he freezes or something bad happens there is going to be a wipe. I've seen cases and seen stories in this thread were DPS Healers let their entire team die because instead of healing they DPS'd and the entire party died due to the healer not curing Doom or not healing 100% in which the spell then kills everyone.
You get anxiety but most people's anxiety might be worse than yours. Going through an entire run keeping your team on edge because you are barely healing is just asking for problems because you can only stress people out so much.
As for DPS I agree. DPS are pawns, if they die you could easily wait a minute or two or even three to revive but the tank has the entire team on his shoulders if he falls chances are so is everyone else.
But people should really consider their personality before rolling a class even if they look good or they think the class is cool. Its like being a person with road rage and using cruise control in the slow lane. Either you learn to calm down or you go crazy and do things your own way.