People who gets bothered by people sharing something difficult in their life are probably shitty people in real life.
Or they could be just over sensitive, maybe even depressive and just try to shield themselves. Anyway, it's ok to share, but one has to know the limitations of sharing: it can help, but it can't replace the time you'll need to accept what happened, it can't replace what's lost. It's a temporal patch, mostly single-use.
Personally, I think it depends how one shared those experiences. You can be modest about it, leave a door open for hope, even humor or you can just pretentiously wallow yourself in self-pity, parodying feelings. I sympathy with both, losses can be devastating, but the difference in character won't escape my notice.