Eating more food overall will help, and yes, eat more carbs. Try to eat more nuts, fruits, sweet potatoes, carrots, and other higher carb type veggies. Don't go crazy though. Just start off by adding a little at a time until you see yourself gaining. Maybe add an extra piece of fruit or two each day for a week, and see how you do. If you are still losing, add some more. However, you probably need more protein and fat too. Add a little more to those categories as well.