Share your experience!
My Xperia P is forever hanging, I don't know if its because of the 3x fell from the table to the ground or because I haven't updated it's system? Is there a place where I can have it updated cause I don't know how.. I'm from The Philippines by the way.. 
maybe you have alot of apps installed.
try to repair your phone using this http://www.sonymobile.com/global-en/tools/update-service/
just install and follow instructions
please make a backup
Not too many, I have 11.26gb available internal memory. What's the effect if Xperia P fell from a chest high to the ground?
most probably some loose things inside. but i suggest you try to check if it is a software problem rather than hardware that is causing the phone to hang, if there are many apps running in the background that may cause hang ups, try to reboot your phone.
how to reboot? sorry I just had my phone few weeks back, I don't really know much on how to use it, its a lot different from blackberry phones you know..
reboot=restart..
and also there was a time when my phone hang and when I opened my messaging it says no conversation stored but I havent deleted anything I restart it several times no luck but when I totally turn it off and reopen it , it appeared already, was that likely to happened? cause even in media player (album, walkman)
most likely it is software problem, I suggest you follow my advice above and repair your phone,
tip: select the factory reset option while repairing/updating, but be aware it would delete all user data