I'd say listen to your body. You will know when your body is in starvation mode as you will feel incredibly hungry. Then all you have to do is up your calories in fats not carbs and you will come out of it.
I'm also a bit worried, a few months ago I used to eat like 3.5-5kcal a day, then I dropped to 2kcal per day, now this week I'm in a high-protein diet, eating around 900-1200 cal a day and feeling incredibly satisfied, can the body go into starvation mode and make me retain weight even if I'm not even slightly hungry?
I started my weight loss journey seriously on oct 18 of 2012, and so far: