The way I describe it, is how it feels at a loved ones funeral. The feeling is grief like, almost, it's crippling.
Even worse so if you've had to suppress it while being at work or around others... As it comes back tenfold when you're alone. How else can I make others understand?

When you say mood swings, people say oh I'm a bit like that etc and it's so so frustrating. Not on such soul destroying levels...