A fake cry involves tears but no inner turmoil. The tears are so surface and even when you're crying you're thinking "that's it? I can't get a deeper cry?"
A real cry comes with heaving sobs from an ancient place deep down. A cry that feels like your releasing years of your life and everything you've ever cried about is suddenly happening all over again.
A fake cry is like you're trying to give yourself attention but then you realize you're also kind of hungry and you might want to take a shower. A fake cry is what you get when you're actually having an anxiety attack but those suck so hard so you try to convince your brain that what you're feeling is sadness and not anxiety.
A real cry makes you feel alone in the world, so alone that you start believing in God even if you know you already kind of believed in that sort of thing but you don't want to tell anyone.
A fake cry can also be a very short-lived real cry if it's an empathy-type of cry or a cry you get from a movie or a book.
A real cry doesn't make you want to die but it might make you super philosophical and have you questioning the reason for your existence and what not. A real cry will make you surrender the control you think you have over the universe. It also makes you sleepy. It also makes you feel better.
If it's hysterical, it's historical.