I get where you're coming from. It can be hard to meet other people in your area who are into guro who you can talk to and hang out with. But I would not go public on Facebook or anything tied to your actual identity. That's just asking for trouble.
Personally I have told some close friends who I could trust to understand and who are into similar hobbies. I started by showing them some guro hentai anime (Urotsukidoji, etc.) to see what their reaction would be and test the waters first. If they thought it was cool then I'd expose them to more content and gradually open up.
After a few years, I built up the courage to tell my girlfriend (who is now my wife). That was tricky and very scary... but I think it's really necessary. Otherwise you'd be constantly be keeping secrets from the closest person in your life and that just would tear the relationship apart.
I have not told my parents or relatives because... well, that's just weird. Does anyone talk to their parents about any porn-- guro or not?? Not anyone I know... :-P
It would be cool if there were some sort of classifieds where people interested in guro could meet others in their area. I lived in Japan and there are several events (Comiket, Ryonaket) where you can buy guro doujinshi and meet people with similar interests. Not so much in tn the US, though.... :-(