Overheated, damage possibilities?

[arg0naut]

So I overheated my 91 Turbo

Was blasting the heater up a snowy hill because my temp gauge was getting a bit high. Got to top of the hill, turned off heater cuz its all downhill from there. Temp gauge still goes up... turn on heater, but no heat comes out... Know I'm in trouble, start to hear a high pitch "beeeeeee" sound from the back, temp gauge at 3/4. Pull over when I can, steam coming from the back. Turn off car (since heater isn't venting anymore) and open engine lid. Let car cool down, coast to somewhere safe. Add more coolant, brownish mixture comes up, so oil in coolant. No noticeable leaks under the car. Towed back home.

Noticed too that my blow-off wasn't blowing off going up the hill. Maybe an indication of turbo problems?

Wondering if anyone could let me know the possible damage I've done to the car. Blown HG of course, but there is a possibility of a warped head too? Thermostat is probably stuck since I wasn't getting hot air? Going to take it to a few mechanics in the area and see what they say. Was hoping you guys could point out any other issues I might have so I can get them all fixed =/

Got my 2 in November... man, feeling pretty depressed.

EDIT: I found the oil in the coolant when I tried to add more coolant. I only added 1/4 gallon before it topped off. Started the car for a few minutes, shut it off, opened the coolant cap and the mixture of coolant + oil shot back up at me.