Hi,
I can understand how you feel. I had 13 weeks off from December 2008 to April 2009 and really couldn't see a way out the other side. I too am in a fairly pressurised job, and expected to perform. I am usually a very confident person regarding my job - in fact a received a colleague of the year award in 2008 for my work, so I know that am good at my job; but confidence ebbs away when you are depressed and I don't feel like that same person anymore. Since my return to work I improved somewhat, but reversed big style after I had an accident in December where I fractured a vertebrae, meaning more time off work, but this time being physically unable to do anything that might help, such as exercise and socialising. So at the moment I'm feeling very much like you. I too feel extremely low and anxious when I wake in the morning, so much so that I really don't want to leave my bed, as it feels 'safe'. My mood improves slightly throughout the day and I probably feel at my best early evening. Do you have a hobby, or an interest? I have a horse and have lost interest in my hobby, even though at one stage it used to be my world and I loved competing. I don't want to sell him, as I know that when I am well, I will enjoy him again. But at the moment, nothing excites me and it is a real effort to do anything. So, I can relate to your feelings, so don't feel alone, because you are not! I try to think that I have come out of the dark hole once (if only for a short while) so there is no reason why I/we can't do so again. It's just so difficult in the meantime when you are feeling so s***! x