Viral upper respiratory infection (URI): Given the child's symptoms of cough, vomiting, and a history of difficulty sleeping, a viral URI is a common and likely diagnosis. The bloody nose could be secondary to nasal suctioning or dry air, and the increased cough and vomiting could be symptoms of the URI.

Croup: The mother's concern about croup is valid given the child's history of this condition. Croup is characterized by a barking cough, hoarseness, and sometimes stridor, which could be exacerbated by the child's history of laryngomalacia.
Allergic rhinitis: The child's symptoms of cough, vomiting, and bloody nose could be related to allergic rhinitis, especially if the child has a history of allergies or exposure to allergens.
Gastroesophageal reflux disease (GERD): The vomiting and cough could be symptoms of GERD, which is common in infants and young children.

Epiglottitis: Although less common, epiglottitis is a life-threatening condition that requires prompt diagnosis and treatment. Symptoms can include difficulty breathing, stridor, and a muffled voice.
Bacterial tracheitis: This condition can present with symptoms similar to croup, but is caused by a bacterial infection and requires antibiotic treatment.
Foreign body aspiration: The child's history of vomiting and cough could be related to aspiration of a foreign body, which is a medical emergency.

Pneumonia: Although less likely given the child's symptoms, pneumonia is a possible diagnosis that should be considered, especially if the child has a fever, difficulty breathing, or other signs of respiratory distress.
Inborn error of metabolism: Certain metabolic disorders can present with symptoms similar to those described, although this would be a rare and unlikely diagnosis.
Vascular ring or sling: This is a rare congenital anomaly that can cause respiratory symptoms, including cough and difficulty breathing, although it would be unlikely given the child's age and presentation.