Christmas, I have a toddler, and absolutely, it's tough handling his food sometimes, and it is almost always me because of his father's work hours in the evening. I used to tell myself that part of the reason I was doing this was for him, that I didn't want him to grow up around a mother who was obese and had a complicated addictive relationship with food. I look at his completely natural relationship to food - if he's not hungry, he won't eat, and he stops when he's full, that food doesn't mean lots of emotional stuff to him etc - and try to learn from it.
And actually, as you say, these sachets don't really compute as 'food', although they're fuel, so you're probably, if you're anything like me, learning to live without a regular treat or comfort you've relied on. I've found it really instructive. It seems to me that I was bandaging myself up with food to blunt feelings and issues I couldn't bear dealing with. Eating was an avoidance tactic. So no wonder you're upset, but maybe it's a good thing to let yourself feel?
Another thing I found helpful was thinking that this item of food was still going to be there in the future, I wasn't not eating it forever, just not now.
Keep going through the first three days, and it will get abruptly easier, and you'll have lost so much weight your first week that you'll be motivated to keep going.
And Choc, I completely forgot about the cold - yes, you definitely feel the cold more in ketosis. I started in hot summer weather, and am not someone who feels the cold, but I was freezing.