i have always felt that this is strictly mine to deal with. it is unfair to burden anyone else with it, even if they express a willingness to help. i cannot explain it in a way that makes sense to anyone but me and even if i could, no one can possibly know what to say or do. it makes everything awkward and puts an unreasonable strain on the other person who cannot know how to help and feels a responsibility that is not theirs. i made the mistake of telling other people on two occasions. years ago, i broke down and told my wife who interpreted it, at different times, as a plea for attention (it wasn't), an effort to blame her (i'm not even sure what i was supposed to be blaming her for), and, most often, as an incredibly selfish thing to even think about because it would destroy my kids (she grossly underestimates them and overestimates my place in their lives). the second time i told anyone was in a supposedly anonymous message to a suicide help service. that one resulted in the police showing up at my place of employment (bizarrely, in full tactical gear), and me being involuntarily committed to a psychiatric hospital for almost 2 weeks, after which i was fired from my job.
whether it is a good idea to tell friends or family (or anyone else) about what you're thinking depends on the other people in your life, i think. but for me, i will never, ever tell anyone anything. i will carry it all with me to my grave -- and very soon.