Have you spoken with your doctor about the feeling? I've heard that a person can develop disassociation disorder. To be honest - I don't know that much about it except that a person feels detached most, or all of the time.
If you haven't, you should definitely speak with your doctor. At the very least thy may be able to point you in a direction that will be able to help you feel better.
Seriously, doctors deal with anxiety and depression on a daily basis. If that is what's contributing to you feeling this way - it's highly treatable.
Hang in there. Keep us posted!