1995 isuzu rodeo overheating

my girlfriend drives a 95 rodeo that is a complete headache. Im 24 but have ben in the auto industry my whole life in the parts dept..Now ive never worked for an isuzu dealer but now i kinda wish id had.I have noticed an antifreeze burn smell when we get out of the vehicle. Now its escalated into a problem.The engine has started to overheat.I checked the radiator when engine was cold and had to add alot of fluid to top it off.I started the truck back and filled it to max level once the radiator would not hold anymore.It is still overheating. Both upper and lower rad hoses are getting extremely hot but not leaking. i have squeezed both of them and i feel hot antifreeze in both of them but can not tell if they are flowing thru or not...anyway i just need some direction....my guess is thermostat is stuck.....someone please enlighten me...will

It seems that some or may be most of the passageways for the coolant to flow in the radiator is clogged up and therefore reducing proper heat transfer.