Iphone memory full despite clearing plenty of video&pictures. Can’t even use gmail because of this

despite having 48 GB of storage in I cloud and supposedly having transferred all of my pictures to the cloud the icon in Storage sttings is showing 1 percent. I have no internet access other than the iphone itself and do not have the facility to upgrade using a cable connected to a mac book or other device.

my phone has been rendered useless as a result of this.