Hello and welcome to HCM,
Fever with decreased appetite and increased sleepiness could be due to viral infection.
Viral infection is usually characterized by
low grade fever, body aches, weakness and decreased appetite.
The muscle spasm that you have mentioned could be due to generalized
body pain.
Viral infections are usually self limiting.
Antipyretics can be taken for fever e.g.
paracetamol.
In case the fever goes too high wet strips can be used.
Analgesics or pain killers can be used for the associated body pains.
Nutrition has to be maintained despite low appetite.
Light food with maintenance of hydration by taking fluids has to be done since fever causes loss of fluids from body.
In case these measures do not help, you need to consult your doctor.
Thanks and take care
Dr Shailja P Wahal