having trouble eating enough....=/

Okay so I set my calories for 1200 - I'm on a semi ketogenic regime. I do eat carbs but I keep it under 20g a day. My carbs I do eat are reserved for veggies and a little fruit.

But I find that I am barely hitting 1000 most days. I'm just not hungry tbh. Plus I exercise (take protein supplement). I eat fats but I try to stay low cholesterol because I have a kidney stone issue.

Because of my kidney stones I drink close to 4 liters of water a day. Give or take.

I'm a bit concerned. I'm dropping weight very fast which is good. But I think that I should be eating more.

Anyone have any insight?