Thanks for your query.
Your child is having fever
which is mostly viral in nature and takes few days to settle.
Feeling tired and drowsy is a part of ongoing illness.
as per dosage every 6 hourly till fever is above 100F.
Do tepid sponging if fever is above 102F.
Give plenty of fluids and soft bland diet .
He should take proper rest.
In case of increasing fever/lethargy
or refusal of feed take him to ER.
Wishing your child good health.