overheated engine

I'm affraid that I overheated the engine of my '93 PA. I haven't realised that it's loosing coolant (the 'coolant low' lamp works but it didn't turn on). After about 5 km the red warning lamp next to the temperature gauge turned on (the temp was about 90 - 100 C). I turned off the engine and I've found the tube that goes to thermostat is disconnected (I've no idea how to explain it in english). I've refilled the cooling system with about 6 liters of coolant. The engine is powerful, runs quiet and perfect as it did before - what do you think?Is it very damaged?

if you overheated it you could have damage to your valve cover gaskets, your head gasket, and your plastic intake manifold. id check for water in the oil, or oil in the coolant. to make sure all of your gaskets have survived.

Watch for white steam persistent smoke coming from the exhaust. Sweet smelling exhaust.
Watch for oil in the coolant system.
Watch for water in the oil. Choclate milky color oil.
Watch for missing coolant. Levels mysteriously fall.
Check your plugs for discoloration. Burning prestone.

If any of the above. If its not real severe, drive till you can afford the $$.(opinion), or then replace the headgasket. $700 (or car)

If none of these.. YOU GOT LUCKY.

Good Luck