Hello. I'm sorry you're having a rough time.
Let's start with food, here. People who are prone to depression or anxiety sometimes find they need more starchy vegetables than others. Definitely be sure you're having at least one fist-sized serving of some kind of starchy vegetable each day, and for now, since you're already feeling down, you might try having a serving at each meal until you feel better, and then you can work on figuring out how much you need each day to feel best. Also be sure you're eating foods rich in omega-3, like fatty fish such as salmon or mackerel. Getting out into the sunshine can help, physical activity can help. And of course if feelings of depression continue or worsen, please talk to your doctor.
You are currently experiencing a lot of stuff -- lack of sleep, the neighbor's death plus the stress of worrying about telling your daughter about that death. Some of the depression you're feeling now may start to resolve as you deal with these things. It's definitely normal to have ups and downs in life.
I think you're right about the not being able to do the emotional eating thing contributing to being more sad. I noticed that too during my first whole30. It sucks to actually have to feel all the negative feelings, but in the long run, it's better to learn a healthy way to deal with them. I find journaling about what I'm feeling helps. It can also be helpful to cry or yell or slam doors or whatever it is you feel like doing because if these emotions (as long as what you feel like doing won't hurt yourself or others). Meditation, exercise or any kind of physical activity, or talking to a friend can also help.
As for the focus on weight loss, I do think it's normal to be concerned about that, and to want it to happen as fast as possible. Try to focus on the non-scale changes you see. Definitely don't weigh yourself, that will just contribute to focusing on weight. Set non-weight-related goals, like to walk or run farther or faster, to lift heavier stuff, to keep up with your kiddo better, to take the stairs instead of the elevator -- pick something that works in your life and focus on it. If you get healthier, the weight will sort itself out. You might find this article helpful:
You can also Google whole30 weight loss, or dear melissa weight loss, and find others.