Hi dmydlack, welcome!

Feeling lightheaded and fatigued can be caused either by dehydration, potassium deficiency or both. Are you drinking plenty of water? You need at least 2 litres/64 oz PLUS another 250 mL/8 oz for every 25 pounds you wish to lose. Yes, it's a lot of water, but you'll feel a lot better for it.

As for the potassium, you can either take tablets or use a potassium salt such as No Salt - available in supermarkets with the ordinary salt. You should be taking about 400mg potassium daily.

It is important to drink plenty of water while taking extra potassium. And if you choose to take the tablets, always have them with food, or they can irritate the stomach.

It's also important for anyone who takes fluid tablets or blood pressure tablets to check with their pharmacist or doctor before taking potassium supplements.

You may also feel better if you add a calcium & magnesium supplement - assuming you're not taking one. A total of 1000:500mg is desirable.

Congrats on already losing 15 pounds. I hope you feel brighter soon.

Rosebud