Clearing Whatsapp Chats Filled My Internal Storage

Question

I have an 8Gb phone but it's storage usage was very healthy - less that 3Gb used.
I decided to tidy my Whatsapp account by selecting chats one at a time and clearing them [ also selecting the delete media from my phone] so as to keep my storage usage low.
Suddenly I get a flurry of notifications saying that my storage is full and some apps will not work.
When I look at storage from settings and select **Internal Storage**   it says  4.44 GB used of 4.54 GB and the bar is showing almost to the end stop.
Below that it shows  Apps - 1.49GB  and Cached Data -  1.84MB
Sure enough most things I try and do will not now work because of not enough storage messages.
What has gone wrong?
Powering off and on doesn't solve the issue.
Tried connecting to my macbook to backup photos etc. but it can't see the phone

HELP! it was working fine until I cleared those chats.
John

Lindsay mcdaniel · Answer

Just clear your cashed data!
Every time you use your phone you accumulate a little cashed data. 
This is not important data. It is just what you have done with your apps.
You should clear the cashed data on a regular basis.
The fact that that notification pop up when you cleared your chats was purely coincidence.

johnobirches · Answer

I tried that - there wasn't much cached data anyway.
It was 3 or more GB which instantly filled and prevented me doing anything - I did a factory reset and lost all my photos and contacts.
Warning - the factory reset also erased the SD card which surprised me to say the least.
You live and learn.
Thanks anyway for the suggestion

Lindsay mcdaniel · Answer

Are there any files in Internal storage that you can delete?
I found a few files in mine that I didn't create, and they were empty but still using storage.

johnobirches · Answer

I didn't have a file manager app and couldn't download one because the storage was showing full.
I've started from scratch after the factory reset.

Thanks