I do try to distract myself when negative thought cycles come up - not the same as compartmentalizing, I guess, but it often helps. Not always, but enough that I keep trying it as a strategy to manage things.

I also find that there's a lot of value for me in writing about what's bothering me. It gets it out of my system, so to speak. It doesn't solve anything, but writing often helps you think through the issues you're trying to address, so I really support that effort. (Of course, exercise is great too, but I know you're already diligent about that!)

There are many ways to write public/private as you need to - the suggestion of Google Docs is good and fully private unless you choose to share it with specific people. I have an anonymous blog, though it's linked here, and if I wanted I could password protect some posts and give out the password on request - or not at all. I like the ability to get feedback from others, which makes me feel understood and sometimes includes different perspectives or tips that help me out as well.

Another nice tool is http://750words.com/, you might want to check that out. It's a private online space for working out your thoughts. Sometimes doing the writing online feels "safer" than anything stored on your computer, and this is a way to do it without worrying about forgetting to make something private.

Sorry to hear that you've got another thing to worry about - it seems like you've had more than your fair share!