Nannoo - you are too hard on yourself, please relax, so much stress is not good for you and raises the old bg too.
Is there anything that can be done to make the job a little less stressful? Get together with your colleagues, talk about issues, I have a very stressful job too and work in a high pressure environment but we all discussed things and we came up with some good ideas to help lessen the load.
Re not having time to cook, I think this is because you find it too hard to adjust to this low carbing thing, when I read that you just grabbed a sandwich but then you felt guilty about it and of course this causes you stress because you feel that you failed.
Nannoo on really busy stressful days I havent got a chance to scratch my a**e never mind prepare lunch I just whizz into the nearest supermarket and buy something really low carb, eg cucumber/celery/cherry tomatoes and a tin of fish or salmon parcels (just sliced thin salmon filled with prawn mousse) or thinly sliced salmon filled with cream cheese and rolled up, or salmon and boursin cheese you can make up your own roll ups, you could also buy some cooked meat from the deli counter and salad leaves and a dressing (or make your own at home it will keep in your fridge for about a week or so) just make sure its not made with sugar, any of these take up no more time than buying a sandwich?
You could also shove some parsley, cucumber, tomatoes and a bit of onion into your food processor, whizz up a moment or two so everthing is just chopped up a bit but not mushy, put all in a container, season and add feta cheese, stir through and you have a very nice Shopska salad to take to work with you, its all done in less than 5 minutes.
I love my sleep ins on weekends and dont really feel like cooking much during the week, I have cooking sessions on a weekend afternoon or evening, and then freeze in portions, vegetables bakes, ratatouille, veggie mash, soups, etc all freeze really well, so you come home from work and just defrost, as simple as that. Buy lovely thick creamy greek yoghurts, I add blueberries or strawberries or chopped nuts and a bit of cinnamon and sweetener of your choice, make up a chocolate mousse (Dr Katherine has a wonderful recipe posted in here somewhere), divide into portions, it keeps around 3-4 days in the fridge.
Another thing that can save lots of time is having your food delivered, this saves you dragging yourself round the supermarket which is often stressful and frustrating.
I hope that some suggestions here give you some ideas and that you can reduce the stress in your life. Cut down on tea/coffee anything with caffeine and drink soothing herbal teas instead, at least now and then, as I said, be good to yourself
All the best
Karen x