Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.
About the GPS - it seems completely reasonable to alert the dealer, right? I don't drive or own a vehicle, but assuming this car is brand new ALL of its features should work, and if they don't, they should be fixed. So, raise some hell.
It sounds like a lot of things have happened at once and are likely overwhelming you (even if your meds make you feel sort of empty). Something that's helped me is the fact that there are some things I can influence or take charge of and other things I can't. You can't control your instructor. If your entire class failed this assignment, clearly there is something more going on than the idea that you're all somehow stupid. Try to take comfort in the fact that it was really difficult for everyone involved, and no one got it, and that maybe your instructor needs to rethink her/his approach instead of flipping out about it, which helps no one.