mobile

I have a Note II with the latest firmware available. I have been having major wifi problems and roaming issues. My battery hardly lasts until 3pm and wifi just kinda dies on me. Mobile data runs slower than it used to and I don't get on 4G as much as I used to. This all seemed to start when I received the KitKat update. Is there a root fix for this issue or should I get a new phone?

Note: I have tried factory resetting and only installing most used apps.

Any help would be appreciated. :D