I do the same thing, too. It always helps to have a separate, objective person provide some reassurance. I was obsessing a good bit just yesterday about heartburn/reflux, and just knew I was probably on my way to getting esophageal cancer. It's been in the news a lot down here lately.

My husband said he really didn't think I was probably dying of anything just yet. . . . but that I should be very alert and hypervigilant just in case advanced cancer truly did come on real quickly. After that, I calmed down. (And smacked him with a pillow.)