Eat healthy fat as well.
Try carb cycling with 3 high carb days following 3 low carb days eat whole foods/wheets and low gi carbs like oats sweet potatoes and whole wheat products. Eat 20 calories per pound of bodyweight drink 3 to 4 liters of water with a glass on empty stomach in the morning( gradually increase this) 1 to 2-3 grams of protein per pound of bodyweight and good workouts will help you gain. Don't forget the healthy fats from peanut butter nuts olive/coconut/fish oil and any unsaturated fats remember the ratio should be 52 %carbs 32 % protein 12-15 % fats take a multivitamin alongside too. Hope this helps :)