Pin 13 Fried/Dead?

Hi, I recently purchased an Arduino Uno R3 and have had it for a few days.
When I first got the microcontroller, it was working fine and the pin 13 LED was blinking when the blink file was uploaded. However, I was in a school lab today and when I attached a breadboard circuit to the Arduino's PIN 13 and GND, the circuit would not function (was a simple resistor and LED circuit). After this happened, I tried to reupload the blink file, but the LED would not light up again! The two lights below marked TX and RX blinked as if something was being uploaded, but the pin 13 LED does not light up at all. Also, when I attach a shield (that doesn't use pin 13), programs works fine with that specific shield.

I'm pretty sure I fried pin 13. What should I do now?? Is it possible to replace the LED or can I just live without it? :fearful:

p.s. I was running windows

p.p.s. I was also using a different voltage source when attaching the circuit. It was at 12V so I'm 75% sure I fried it

Can you post the exact schematic you did in the Lab?
And the resistor value.

How did you connect the 12V source?

The image attached is the schematic. In order, I connected pin 13 to the LED's long end, then the short end of the LED in series with a 240 ohm resistor, and then finally back to GND next to pin 13.
The 12 volts was supplied through a triple output supply, with the positive connected to Vin and the ground connected to the GND next to Vin.

arduino to LED.png

Schematic is ok, I don't understand how could it be damaged.

You can upload code right? Then Arduino is not dead, and only pin 13 would be dead, weird...

So is there any way to fix/replace the pin/LED? Or should I just live without it?