I really like the idea of challenging yourself to a number of days, and see what weightloss comes. Nice one.
Has someone recommended 1100 calories to you? It's not very much, and I wonder if eating so little while exercising a lot is a) slowing down your weightloss and b) contributing to your low mood.
I'm not an expert at all but have in the past slowed my weightloss at 1000 - 1200 but hastened it at 1400 - 1500. I'm now following a lowER carb diet, which is also highER fat. I've lost 7.5lbs in a month, 4 of them this week. I don't want my non-expert view to confuse you but I don't like the idea of what you eat/don't eat making you sad ~ I've been there too.