First of all, you're doing GREAT.
Second of all, the human body can be quite the bitch. You keep a routine and work hard every week - you put in the same effort day in and day out - you lose a good amount of weight for a few weeks in a row - THEN...nothing. There's always that one week here and there where the scale doesn't seem to move. Why? Nobody can really tell, but that's just life.
The truth is, the scale might not move sometimes for a number of reasons - your body could be holding onto to excess water weight, your body just might be tired and storing some of those calories instead of burning them, you could be building muscle which weighs more than fat, for some reason your metabolism might've slowed down a little, etc. There's a ton of reasons why we all have those weeks where our weight doesn't go down (and trust me, we ALL have those weeks), but try not to let it discourage you.
Hell, ask my wife - she'll tell you about how frustrating it can be when the scale doesn't budge. She'll bust her butt for a week or two, eat right and exercise, and lose five or six pounds. Then, she'll do the same exact thing for the next week or two but not lose a single pound. Then, she'll have a cheat day, eat some pizza and have some ice cream aaaaand? She'll lose three pounds the following morning, HAHAHA. It's just life. It's frustrating but it happens...to everyone. So, don't let it discourage you. Just keep doing what you're doing.
Yay for 111.1! Losing a kilo a week is actually the normal, healthy way of doing things. Losing too much, too quickly for too many weeks after another you will have more trouble keeping the weight afterwards so maybe it´s a good thing that things are slowing down a bit. You´re still doing awesome.
I'm not active in this thread because I started a new one not so long a go. My progress has become very slow due to work but I'm at least maintaining my weight and that is satisfactory at the moment. 