No, you have not damaged your metabolism. All animals on the planet live by intermittent fasting. Well, except for two legged one. Your body is programmed not to eat everyday, and four or five times.
I have done so many fasts in my life, I can tell she you that every fast is different, I had a few fasts when I did not lose any weight in first few days and then I had a few when I lost 5lbs in one day.
Honestly, your weight is perfect for your height. But fasting will bring some healing and cleaning needed to your body and mind.
Don't worry keep going. Tomorrow may be a different day and you will lose a few kilos.