You have acute laryngitis with hoarseness of your voice and an unclear voice.usually it's due to acute viral upper respiratory tract infection and lasts for 5-10 days.Since your cough has reduced there's no need for continue antihistamines as they dry up vocal cords making it harder to clear up secretions
Next Steps
Vocal rest (avoid whispering, as it promotes hyperfunctioning of the larynx):
If you must speak, use a soft sighing voice
Humidified air
Increase fluid intake
paracetamol 650 mg 3 times daily
mucolyte 10 ml there times daily
Symptoms usually resolve in 7–10 days, in viral laryngitis