Well at simple sight it seems that is the infamous memory leak, but are you willing to do a couple of things just to try to see if it gets better?
1-) Do you have a theme installed other than the default? If yes, please put back the default.
2-) Check your Apps Cache in Settings-Storage, let us know how much space it's using and then clear it.
3-) Do a Wipe cache partition in Recovery Mode. Turn off your phone and Press and hold Volume Up, Home and Power buttons until you see the Android robot, then browse the options with the Volume buttons and use Power button to select.
Remember, you have only 2 options here, wait until there is an update with a fix or try to look for the cause and fix. I think you won't lose anything other than maybe 5 minutes at most.