note 5: something eating up my storage

[Android Central Question]

I have a 32gb note5, and for some odd reason has something that's eating 18-19gb of memory. I checked everything on the fone, internal storage, apps, caches, and only got a total of 11gb but it shows 29/32gb. I wish to know how to get rid of that random 18-19gb worth of memory without resorting to factory reset, thanks.