I understand how you feel. I've been severely depressed before. Depression can get so bad that eventually you can't even leave your bed. It's a terrible feeling but the good news is that the depression will lift. If you do not already have a pdoc you should find one and set up an immediate appointment. There are a number of medication that will help you break free from the depression. When the depression gets as severe as you described you need to get some help. Isolating is natural but you should also reach out to your support network and let them know what's going on.