Is 1200-1300 calories really that bad

Hello I am an 18 year old 5’7 male and I went from 245lbs to my current weight of 168lbs. I want to reach my goal of 155 and these past couple months I’ve only been eating 1200-1300 calories. I’ve read online about how it’s bad to go that low because you’ll lose muscle or cause your metabolism to mess up but I feel fine. I’ve been gaining a good amount of muscle and eat a little more than 100 grams of protein a day and take vitamins. I just wanted to know if my eating habits are bad and will harm my weight loss.