Dear friend, welcome to HCM!
It is saddenning to know this.
He has a skull infection
as per your description and is behaving irrelevent, becoming drowsy.
This indicates chance of getting meningitis
or brain abscess
This calls for urgent admission to a hospital, a CT scan
of the brain, urgent antibiotics nad if required, other life saving interventions.
You have to do this despite he refusing or behaving abnormal and rush him.
he may slip into coma soon, throw a fit or worse..
Take care and please keep me informed of your progress.
I hope to have answered your query satisfactorily.