"the world is black, the world is white...."

Alright. For those who don't know me, I live in a world of extremes. Black/White. That's it.
Scratch that. I live in a GRAY world. I do, i really do. We ALL do.
Please allow me to start again, then...

The world I live in is gray. The world IN MY HEAD is black and white.

And therein lies the rub; a rub that not even BODYGLIDE can help me with. What to do, what to do? My b/w mind gets me into trouble almost daily; either with myself, or (worse yet) with others. Here's an example of a recent conversation (edited for family viewing, as well as brevity)...
OP (other person): "i know that your virtual friends make you happy, but i wish that you would spend more time engaged with the real people in the house."
MID (my internal dialogue): "fine. i will post to twitter and the blog that I will be leaving cyberspace. sort of a "so long, and thanks for all the fish" post. done ,done, and done."
MED (my external dialogue): "ok. i shall try to be more engaged here, with the family." (which of course, is the ONLY smart thing to do......) more than that, though, it is what I TRUELY WANT TO DO.

I just don't know how. Or have forgotten how. So i go to the extreme in my 'solutions' for things i don't understand. Monday evening I was shopping with Bryce, and the idea to stop drinking coffee at work flew into my head. So Tuesday I made up my mind not to drink coffee at work, or at least not coffee FROM work. Then my office mate came in the room with a cuppa black coffee that smelled sooooo good that i just HAD to have one, too. So i did.
Why not compromise with myself and have just 1 cup at work, or one every other day, or...something other than NO coffee. See? my black/white thinking (cognitive distortion. read about them here and here, courtesy of my virtual pal over at http://www.counselormusings.blogspot.com/) gets me into trouble, or at the very least sets me up for failure, each and every time.
So why do i do it? Sometimes i think that i do it because it is 'comfortable'. the thought process is known, the outcome is known (although not preferred). Gre/ay thinking is unknown to me, and therefore uncomfortable and scary. It is LONG overdue that I move into the gra/ey. If I don't, my next move will likely be more complicated, and involve cardboard boxes...

What are some things that you know you should be doing but aren't, out of 'fear of the unknown'?