Should I let my mom know who I really am?

She thinks I'm this sweet little girl who's the happiest ever. When in reality, I'm this depressed girl who swears all the time and who's into emo clothes and who has an emo attitude most of the time. I'm not gonna let her know I swear...I would be in sooo much trouble...but I do want to start wearing the kind of clothes that I like. I just think it'd be too surprising for her and I don't know if I should show who I really am. I'm also very into skull designs and she doesn't know that. I just dont know what to do.