Oh shit bro

I think it's generally conflated with nervous or insecure and used in the same contexts, hence the negative connotation. Self-conscious about one's body = insecure about one's body, though the words technically have different meanings I've often seen them used interchangeably in some contexts. I'm not a native speaker though so I might be wrong, this is just what I noticed people saying.

in the positive sense it's being fine with your body and who you are

And in my sense, I dont give a shit about how people look at me anymore in terms of my browser history lol