Car overheating? 99 honda accord

Gauge is going over half way up after 6
miles driving with a/c on. Fans run while a/c
on but gauge doesn't go down. I have
replaced water pump and hoses 1 year ago.
Radiator 2 years ago. Then in the last 3
weeks all 3 sensors for fan, gauge and temp
have been replaced, thermostat. Had system
flushed. No visible leaks. No oil in the
antifreeze and oil looks normal. No white
smoke. No sweet smell from tail pipe. No
rough starts.I had Honda do a pressure test
and hydrocarbon test and it came up with
.005 pm of hydrocarbons in the cooling
system. Diagnosis= symptoms leading to
head gasket slowly deteriorating. I'm having
a hard time believing this as the car runs
good. Any opinions or ideas?it's a 99 Honda
accord L 2.3.  Temps where checked on
radiator, engine, hoses and temp sending
unit and they were all around 180 to 185