Iphone 6 128gb storage says it's almost full

I wake up this morning to a warning that storage is almost full. I check and it says I have 14.1 GB of pics and vids then 2.2 gigs of messages. After that it's all small stuff but doesn't even come close to adding up to the 114 gb of storage space available. Is it some sort of glitch? I've tried shutting phone off and on and didn't change.