it's important to know a couple of numbers -
your height/weight/age
your BMI
your BMR - basal metabolic rate.
your body uses around say 1700 calories a day just to function - to breathe, sleep, maintain, to repair, for organs to just go on beating and working and cleansing and all they do. (that's what your BMR is - the amount of energy your body uses without taking into account the calories you put into it (food) or take out of it (exercise/daily function ie walking & housework)...
depending on the numbers above, we can help give you a better idea of how many calories you need. if anything, i'd suggest you are probably not eating enough (with 1000 calories, unless you are doing a medically assisted liquid diet or similar) in order for your body to have the fuel it requires to function and lose weight.
if you can get the above details, that will be really great and we can help you a bit more.
you can google to check what those numbers are for you - and i am pretty sure ray has the BMI & BMR calculators also on this site.