I'm 5'6" and weigh 113 lbs. Is this healthy? Can I lose more weight and still be healthy?

I'm worried about u. You are already very underweight and that is not healthy. Your body mass index is only 18. Normal is 20-25. Are you a dancer or model or just think you are not thin enough? People obsessed with losing weight even though they are underweight may have anorexia nervosa. This needs medical attention to correct the distorted body image and prevent complications like bone loss.