sounds like you are having a horrible couple of days. i know i have them myself sometimes.
it's great that you still managed to exercise last night even though you didn't feel like it. i hope you got some of those good endorphins from it!
if you're feeling like work is awful today, maybe you can get out for a wander at lunchtime? doesn't even have to be a full on walk, just something to get you out of the office.
i know it can seem like a really slow process, but you have already lost .5kg - and if that doesn't seem like much, go and find something in your cupboard at home that's 500g and give yourself the visiual of what has actually come off your body. once you've lost a couple of kg's you'll find yourself amazed that you've been carrying around extra that weighs that much! it's a powerful way to help stay motivated
also, maybe you need to do some other things for yourself to remind you that you really are worth so much - buy some bath stuff & have a relaxing bath, give yourself a manicure at home etc. i find these things help me to remind myself that i deserve to treat myself well & i am worth it.
i guess there's also an element of how much you let things get to you - i'm beginning to really come round to the power of positive thinking. i've let things get me down in the past, but now i realise that i can choose to look at them in a positive way. it's disappointing that your friend can't make it, but maybe you can reschedule and now say to yourself that it gives you time to do something else (going for a long walk, shopping, even cleaning!).
hope you're feeling better about things soon, we're all here to chat & listen if you need