Awful few weeks.

It is very hard for me when I am stressed out to get into or stay into working out or eating right. When you say there is a lot going on, I am assuming you mean a lot that is not terribly pleasant! Or do you just mean you are very busy?

It's good you are still losing weight. Getting control over your routine again before you gain is great. Do you keep a food diary, on here or on paper? It helps to be accountable and know others will be checking your food diary.

I think when we are stressed out, we are even more focused on what we feel we do "wrong" (like the Mountain Dew you mentioned), and then that is even more draining and exhausting on top of the burden we are already carrying. When I feel overwhelmed, I tell myself to focus on just a few things. I know I don't have the energy or mental desire to take on much more than that. So I may let a soda slide as long as I work out today, for example. And save the rest for days I am not already beaten down!

Erm, try not to worry about having an off day. If you overeat, don't fret- if you have enough energy- do simple exercises around the house to rid the guilt. If stress is the main issue, do whatever you can to relax. I recommend herbal drinks, watching a film or reading a book. Yoga is a good way to keep up with the normal routine when your too fatigued to exercise and have started binging again- it doesn't burn hundreds of calories but will relax you and improve other areas of your health.
Good motivation helps a lot, look at your favourite picture of yourself and focus on the points you want to maintain through your diet and exercise habits. Alternatively, watch a program like 'How to look good naked' or 'A year to save my life'. the first naturally gives you confidence and the second scares you enough to get healthy. Maybe buy a new top, retail therapy is amazing with things like this.
That's all I've got, hope I helped! xx