Richard seems slightly surprised by your tone, indicating that he might have been expecting a far more aggressive reply from you.

He then shakes his head. "I really wonder what's going through your head…. You were never that good, but there was a time when you were at least producing stuff of passable quality!"

With that, he turns around and leaves the kitchen, coffee cup in hand, and disappears down the corridor that leads to his desk.

So, it seems that the entire office is aware that your boss is unhappy with you, which means that something must be seriously wrong.