USB port disappeared and can't sync to arduino

Hello,

I googled plenty but couldn't find my answer so i am forced to turn to you, wizards.

I was playing with my Arduino Uno R3 + 12v + relay + MAC. I am beginner, and although I kind of know what I am doing I may have messed up something. I was wiring and i heard light clicks/switches going off.

In the Arduino Studio i used to be able to choose between bluetooth and usbmodemxxx. When i chose usbmodemxxx i could work and sync. However, now I can't see usbmodem anymore, so bluetooth is automatically selected. I opened the Arduino IDE. On the bottom it says "Arduino Genino Uno on /dev/tty.usbmodem1411. However, when i try to upload the sketch to arduino, I get:

Sketch uses 450 bytes (1%) of program storage space. Maximum is 32,256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2,039 bytes for local variables. Maximum is 2,048 bytes.
avrdude: ser_open(): can't open device "/dev/tty.usbmodem1411": No such file or directory
ioctl("TIOCMGET"): Inappropriate ioctl for device
Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

I looked at the suggested link, but didn't help.

What can it be? Did I fry something? If yes the Arduino or something in my computer (i am still able to plug in a usb thumbdrive and read off it)? Why is this happening and how can i fix it?