I know how hard it is to stop thinking about it after you're worked up. bugs are a big one for me too. The other day I saw a piece of lint on my dog, and spent an hour trying to convince myself it was a flea....even though I knew it wasn't. I got itchy, stared a mole I've had all my life waiting for it to crawl away. I can be really ridiculous sometimes. What helps me try shut it off are mindless distractions - blast music, video games, art, exercise, a shower...basically anything that diverts my thoughts so I forget to think about it.