Playing with a "hidden" handicap

I have a handicap.

There, I said it.

I suffered from a traumatic brain injury (TBI) back in 1997 after getting hit by a drunk driver and going into a coma from a fatty embolism (simple description, it's very much akin to a stroke) Ever since then I have had the "wonderful" experience of learning to understand, accept and deal with the lasting effects of the TBI and accompanying PTSD (nice bonus, eh?)

What people do not seem to understand is that having having a brain injury does NOT make you stupid, but it does affect things like memory (speed and reliability of accessing memories) and the ability to process new experiences very quickly, as in, say, the increased difficulty of a heroic boss encounter in a game such as WOW.

The TBI's lingering effects do not mean I cannot learn encounters. I can. It often takes me doing an encounter many times to fully grasp the variety of things that are going on all at once. This is one of the reasons that every time I have attempted to heal in WOW, I have failed MISERABLY.
Tanking, on the other hand, seems relatively well suited beause MOST of the the time, you job as a meat shield is to get the boss to focus solely, or primarily, upon you. When I tank new encounters I rarely consider what is going on with the DPS classes (you know the old saying, if DPS dies, it's their fault). In BC I was able to amass a decent tanking set, yet primarily did mainly normal version of instances and was able to do a rather good job as time went on. I have gotten a decent amount of compliments on my tanking (particulary from high DPS tier geared players for my ability to hold aggro from them) - not to say I'm always perfect. But when I screw up, I admit and ask for advice on what to do to 'not screw up'.

At the moment though, I am burnt out on tanking. I am really enjoying learning how to DPS with my warrior (which I do rather well at , despite people claiming that Arms spec is no good for PVE). My failure tends to come with complex, heavy damage boss fights in heroics. I die first, I die often and I get kicked - usually about that time I am planning on saying my farewells anyway.

Maybe with time and MUCH better gear I can do better in heroics. Though it does seem like a bad loop of a catch-22 situation: you really need heroic gear to do well in heroics.... *SIGH*