as you stated your child is having pus from the left ear which show he is suffering the otitis media
of the left ear that means the infection of the middle ear which is supporative and the cold
sweats occurs due to the bout of fevers he is having. the best you can do at this stage is to stop any antibiotics he is using for atleast 48 hours and send the pus swab and blood sample for culture and sensitivity to identify the causative organism and sensitive antibiotic against it. however he can use paracetamol
during this period for lowering the temperature.