my system reserved storage got build up and it affected my phone, I can't use my control keys ordata

[Jommybest]

my system reserved storage got build up and it affected my phone, I can't use my control keys and I can't swipe down to access my data usage.

What should I do, cause am trying to clear storage but not working. Is so frustrating 

[Falcon_ASUS]

@Jommybest 
It is recommended that you consider removing apps that you do not use frequently or backing up data to another storage device to free up more storage space. Alternatively, you could consider backing up your data and then restoring the system before using it.
[Phone] How to do the factory reset on your phone？
Sorry for any inconvenience it may be caused.