The patient seems to be having multiple problems as you have listed here.
In elderly people with multiple brain insults it is well known that minor disturbances in serum electrolytes, or any infection like a urinary or chest infection
can lead to significant alteration in sensorium. Since he is Diabetic and having a fungal infection
you need to get that treated plus look for any other source of infection like a urinary or chest infection and treat it effectively.
Also a Chronic Subdural Hemorrhage
associated with the previous fall may be ruled out although it might be less likely.
Usually people post stroke
with these symptoms respond well when the ongoing infection or alteration in electrolytes are taken care of. Hope this helps.