Hello Aimen
Unfortunately I am not 100% sure what a repacked kernel is, but from deconstructing the word, it seems like a stock kernel that has a few additions which are compiled into what is known as a 'repack', and I believe that repacked kernels are designed to work with specific custom ROMs but not all of them, if you know what I mean. The Viper ROM, for instance, uses a repacked kernel rather than the stock one.
Listen, I used a tool to flash the Alex-V's repacked kernel which had the Swipe To Wake feature as well. That tool is called Bricked-Installer. Here is the link:
http://forum.xda-developers.com/showthread.php?t=1749968
It is really easy to use. When you download the kernel you want, it'll most likely consist of two files, a .img one and a .zip one.
1) Download the desired Kernel
2) Put the kernel files into one folder on the desktop, for instance
3) Run Bricked-Installer (don't boot into fastboot mode or anything, just leave the phone running as it is)
4) Follow the easy on-screen instructions on Bricked-Installer and then click Browse in order to search for your kernel
5) Locate the folder with the kernel files inside and most likely only one of them will appear in the search, and if I remember correctly it was the .img one
6) Choose it and let Bricked-Installer do its thing then reboot and hopefully everything will be fine from there
Good luck and let us know how it goes. Glad you had a backup before!