Today I decided that I should upgrade my phone and move to Cyanogenmod 11.
So I downloaded everything, followed every step, made a backup with Titanium Backup, and upgraded.
With (almost) no problems, my phone booted with Cyanogenmod.
At first, everything went smooth, I put all my stuff back in the memory while I sit back and enjoy the speed.
But then everything went bad. I found out all my contacts are gone, all my photos are gone, all of my songs are gone, the home button doesn't work, I opened Nova Launcher and suddenly the lockscreen has been disabled.
I can't close apps because the home button doesn't work. The button on the upper left on the notification center doesn't work (although it worked at first), I don't even get notifications.
There is no physical problem with the home button. When the phone is locked, I press the home button and it wakes it up, but it does nothing besides that.
I also can't access my Contacts app, I need to open the Phone app and access them through there.
Also– I can't receive any calls. It seems the phone knows a call has been made, but it sends the caller straight to voice mail and I need to check the missing calls to see if anybody called.
If it helps, whenever I boot the phone there's a tiny exclamation mark on the top left.