Give yourself time to grieve. I think you DO show signs of depression; having those "bad days" and overeating, the loss of motivation... you may very well be depressed. Depression is not just about sitting in your house crying all the time. While I was depressed, my primary symptoms were lack of motivation and rage. Uncontrollable, unpredictable rage. I never cried, I never laid in bed.
Try and talk to your doctor about it; while you're on an antidepressant, it may not be enough, and you may need additional therapy, a support group might help, too.
It's tough, and I'm sorry, While I'm younger than you, I did lose my father at a young age, so I know a bit about recovering from grief. What was important for me was activity. I had to get out of the house, and DO THINGS. I was 15 and cute at the time, so exercise wasn't even in my brain, but I did get out with friends, and tried to be busy.
Maybe doing things might help. When you feel the urge to hit the fridge go out for some fresh air. Get a good walk, air in your lungs, sun on your face. TRy to reprogram your stress response to something healthier. It's hard for me, because I'm an emotional eater too, but I"m getting there!
Here's a couple of articles here on sparkpeople about binge eating that may help you:
10 Ways to Stop Binge Eating in Its Tracks www.sparkpeople.com/resource/nutrition_art
Stop Emotional Eating Before It Starts www.sparkpeople.com/resource/wellness_arti
This Sparkpeople member turned to running after her mother died: www.sparkpeople.com/resource/fitness_artic