Hi
@jackkk,
First off let me just say that I can totally relate to the depression and suicidal thoughts as I'm also a sufferer.
As for your idea I think it would actually be really easy to achieve.
My initial thoughts would be that people could just create a blog post for their "status" and choose if they want to receive comments on their posts or not. You'd have the homepage setup to just show the blog posts in order of most recently posted. And when members sign up they could be given say a Contributor role to allow them to make posts.
You could add extra features as needed with plugins but the above would be the basic concept.
Hope that helps a bit.