Harmony, if you drink something like Brisk lemonade (don't even know if that's a brand you can get in US) that has a fair bit of sodium, no caffeine and has only 110 calories per can (instead of 150 for Pepsi, for example.)
Or drink things like Gatorade G2 which have salts but only 30 calories.
As for losing weight, take a week to eat regularly and track your food in My Fitness Pal so you can see what you are currently eating and what ratio of fat/protein/carb. Then trying upping the protein to 25% of calories and fat to 30% and see what happens after a week.
MyFitnessPal will track sodium for you too. That will help you make high sodium choices from healthier foods (for example nuts over chips.) Remember lots of healthy foods like spinach, celery, beets, chicken, have sodium in them so you can choose higher-sodium foods that pack a nutritional punch, instead of just adding salt from a shaker. That will help fill your tummy as well as your sodium requirements.