As I see it, RTS is all about multitasking. In first person shooters you can focus on shooting, throwing a grenade.
You pretty much just have to do one thing at a time, so it is really hard to adjust to the RTS style, where you have to fight battles, build up your economy, scout, think about what the enemies strategy might be etc.
I have exactly the same problem as you

six years of playing Counter-Strike have taken their toll on my multitasking ability.
I think the only thing that helps is practice. Play a lot and try to play on the highest level of multitasking that is possible for you. You'll eventually get used to it, that level will shift upwards and you will be a worthy opponent for "ze pros"
All the best
Phil
btw, GPGnet's the same nick as here. Xfire is "hsbyempty".