Nice to meet you Sam!! I am also eating 1200 calories a day and average around that amount of exercise a week (maybe a little more but that causes me to eat more food so i am looking for a healthy balance!!)..
I used to be a big time DC and coffee drinker - still drink about 2 coffees a day but have limited the DC to one a day... I think the additives and sweeteners are just not worth putting into your body! I also dont use artificial sweeteners added to anything anymore (I used to sprinkle equal on strawberries!) as i think it is best to try and be as natural as possible
How much water are you aiming for a day? 2L is a a good happy medium - I drink more if I am working out more but sometimes less which is naughty naughty
Oh also - there is a lot of evidence to advise that having artificial things actually cause you to crave more as you are tricking your body into thinking it is getting calories and when it doesnt get them it acts up!! haha
good luck! ill be checking on ya