mobile

When i woke up today trying to turn off my alarm, i noticed that the phone is choppy and lagging heavily which is very unusual. Initially i thought some apps are updating but this lagging never stopped. So i used the system monitor in FKupdater to check if the cpu is running high, but instead i found out that the disk i/o is constantly running at full. I did some findings and currently there is no per-app disk usage monitor so i don't know what app is causing this. My phone is almost unusable now, can anyone help me with this?

My Nexus 4 is running on older version of ParanoidAndroid which is 3.69.
Android version 4.2.2, and latest franco kernel.