Sometimes when a person starts reading motives into someone else's actions/inactions, it is a way of pushing aside one's own reasons for doing something (and not doing something counts as "doing something" here--its a choice). I know I've done that myself. Its a hard habit to break sometimes, and sometimes it isn't entirely broken, but being aware of what's going on in your own internal subtext helps, and it sounds like you know that already, and that is half the battle. What I've done when in a similar position is to try and distract myself, to get my mind off it (not always successful). Normally to de-stress, I'd go for a long walk, but, of course, that leaves me alone to dwell on my imagination. Lately (the past 6 years or so), I've tried some tai-chi which seems to help more quieting my mind. Each breath in & out clears the cobwebs and each time I do the chi ball thingy, I leave that negative energy behind, pushing it out the door or window. I know its all figurative, but in my mind it helps calm the synapses and gives me a little peace of mind and I'm able to shrug things off a little easier afterward. And sometimes you can just laugh, viz:
http://www.youtube.com/watch?v=UJNRD...eature=related (Mr Happy, approx 5 mins in & Mme Wonderful approx 8:30 in)
http://www.youtube.com/watch?v=PF1gy...eature=related
http://www.youtube.com/watch?v=9Ijwl...eature=related (cats approx 3 mins in)