I was in the same position as you are Varna.
Wrath had made me an arcane mage. I messed about a little with fire when I had the high-end gear for it, but kept falling back to arcane.
In Cata, this all changed. There is so much movement in raids now, that arcane suffers horribly. I had to sit down and learn fire and it took a few weeks before I was comfortable with it. A few more weeks before it was fun.
I still love arcane for it's machine gun spec - though that is not the same any more that arcane missiles is only used to reset the arcane blast stack.
It will take you some time to get the rotation down pat, like any spec. But you will get there