Try safe mode, it lets you know if there's anything installed that could be causing the issue, cause it literally only leaves the software of the phone running, it's from the restart menu, if you press and hold on the power off, it will ask you if you wanna restart in safe mode, press ok and give it a run for a while and check if it would still freeze, if it didn't try uninstalling some apps, clear out some space too. oh the SD card could be a factor too, try removing it and see.
