You know what your problem is? You’re too good. You have found what you are good at and stuck with it. You are the best tank out there, and you have been tanking for your guild for three games now. Everyone relies on you for that. You leveled a (feral) druid alt, and you tried a mage, but the playstyle is uncomfortably different and you’re not good at it. Why be a lousy mage when you could be a great tank?
You are stuck in your comfort zone. You need to go out there and fail. Try a lot of things. A lot. You will be lousy at most of them and you will do dumb things. But a few of them will really work for you. Maybe you are not such a bad rogue once you stop trying to play the class like a tank. Maybe you could be the best healer ever because you know exactly what the tank needs. Maybe you find that one type of PvP is fun, or you miss racing games, or that small publisher made the best little niche game you have ever seen.
the entire basis a major component of our economy: failure is easy to recover from, but success is rewarding and lasting. That is why your game has a light death penalty: try everything, even dumb things, and you can find something new and fun. And if not, if nothing is better or is even a viable alternative, you are still the best tank on your server. You are accepting that role consciously and knowingly, rather than just clinging to the familiar.
Crap, I don’t have do that, do I? I’ve been playing a mage or a healer since like 1999.