Hi, Cristina,
I also suffered from depression before my concussion. It was mild and fairly well controlled, but the concussion made it get MUCH worse. I can really identify with not feeling like you can get anything done.
Probably, at this point, you SHOULDN'T be trying to get much done. Your brain needs time to heal from the most recent impact. You mention trying to drive, going into stores, having a big list of things to do. Is there any way that you can clear your schedule for the next few weeks and just take things easy?
I recently participated in a depression recovery program that focuses on brain health. It really helped me a lot with both my depression and my post-concussion symptoms. It uses natural remedies that help optimize your brain and a lot of them are simple things you can do at home like walking outdoors in the sun. You can find more info about the doctor who runs it at
http://www.drnedley.com
Keep in touch here on the board. There is a lot of wisdom, and more importantly, we have been where you have and know how awful it feels. You can get through this, even though it might not feel like it sometimes.