I prefer tanking
Tanking, from a gameplay perspective, is actually the most kickback job you could play. I suppose dgn mobs would make people skittish but when it comes to basically bosses, there's actually very little to do. Furthermore, you will never get punished for mechs as hard as any other jobs, thus allowing you to survive longer and more importantly, gets you more opportunities to learn the mechs of a fight, especially if it's day 1 raids. There are barely any rotations for tanks and when it comes to cycling cds, all you're asked is to remember the tankbuster or the tank swap debuff (those are far and few in between).
All I can suggest to people who want to tank but are afraid of failure is this: just tank. Keep tanking. Keep at it, find a cushy duty, keep tanking. Don't strive to be a master tank from day 1. Start from the basics and keep upping your game little by little. Own up to your mistakes but don't be shackled by them; remember them instead so you can do better the next time. Find your style but don't brush off beneficial hard facts about the tank job you play as an excuse to hide in a comfort zone that's not actually benefiting anyone but yourself.
The only person that's truly denying you of your tank fun is yourself.