'Fed up' means that you can't be arissed hoovering or doing the washing, or whatever. Being 'fed up' is a facebook status. Depression, deep depression, infringes on every core of your being. It gnaws away until there is nothing of the 'real you' left. I've suffered from depression and anxiety for a number of years. If i wake in a depressed state, there is nothing that can alleviate this during the day. However, if i wake 'ok', it doesn't take a great deal to put me on a downward spiral. I'm not saying that i'm deeply depressed EVERY day, but when i am, nothing matters. That, imho, is the difference.