Yep you're wrong about that. I am a highly emotional being I just express it inside out as it were. Which makes me particularly susceptible to depression and mental loops as my frustration, anger what have you doesn't have an external outlet. My freakish ability to not get upset outwardly creeps my coworkers out as they cannot seem to find my resemblence to humanity...

The other side of the competence swords is when others think of you as machine-like in your ability to perform and therefore cut you no slack whatsoever when you have less than a stellar day. I am frequently held to higher standards and accountability than my coworkers and actually that pisses me off no-end. I am a fair minded person and I think the standards I am held to should be the same as others so I can exceed them if I wish but am not compelled to. Anyway I digress.
My trick is always to withdraw when I feel the rage building, find an excuse to have a cup of tea, rail at the universe with my mind and come back fake and competent. I just file it in my '
get that shit done later' inbox and use distraction to do something else. It's not I don't have emotions it's that I have a method of detaching from them momentarily for the sake of convenience. My desire for completion of my rant is still there but I can delegate it to another time slot. But then again, sorting, delegating and pidgeon-holing is how I go about my day anyway. Although I'm constantly driven to completion, the simple act of mentally assigning a time slot to a task is a kind of completion in itself and satisfies in the moment.
You sound like the way I get when I forget to do my mental sort and delegate. When I've just got a 100 things on my to do list and none of them have been prioritised. I'm allergic to clutter, especially mental clutter and I do experience heightened anxiety and manic states when I've not done my mental house cleaning.