Maggie,
It is not unlikely that you would have comorbid depression with your existing anxiety. It is understandable if you do and,in my opinion, it is a normal response for someone suffering severe panic and anxiety like us. I mean, look at the facts: you want to go places and do things but you are too scared to go, you want to be normal, successful, independent, but you can't seem to do anything alone, you want to hang out with other people and have fun but you don't want to share the fact that you suffer from panic disorder and what would they say if you had an attack while hanging out? These are things that I have struggled with and it started to depress me. Not only that but our energy is wrapped up in panic and keeping it away that it leaves us physically, emotionally, mentally drained. Also, when anxious, I find that I am very irritable on top of being exhausted. I have been where you are and it will get better. I truly understand how you feel though. After having unrelenting anxiety for so long, it is only a natural response to get depressed but you can get out of it. Alot of it is the negative thought processes that occur in depression and anxiety, thoughts like "it will never get better, I am doomed, I will never be normal again, I just want my life back". You have to change the way that you think and the way that you cope with things. If you can take them, an SSRI may be able to help you and you may want to talk with your doctor about that. Me being the medicine phobic that I am had to see a psychologist who has helped me and continues to help me with my negative thought processes, how to handle stress and coping techniques, and understanding how certain things can trigger anxiety and depression and how to recognize that and stop it before it does. You will get better with time but you have to have patience (which is hard to have as an panic sufferer when you want relief and you want it now ;-) Hang in there, be strong, and have some faith. Good luck.