Boot Loop CyanogenMod
This seems to be a problem created by a failed installation of CyanogenMod.

Please make sure you have read the notes on the CM-Wiki:


  Note:
  
  On 2011 models, the kernel will not update when flashed in recovery, so the kernel must be >updated via fastboot every time you flash a new build of CyanogenMod.


As far as I know you should be able to exit the loop by long pressing the power button until the screen goes black.
Also I suggest you install CM11 as Android 4.4 has far more support by the community than 4.1-4.3.

Before installing any new rom I would consider installing a stock rom to flash all possibly missing files and then begin to flash everything again (recovery, rom, kernel etc. in that order)