iPhone 8 storage is full

My iPhone 8 has 64gb of data but I keep getting the memory is full message. (I have 128gb of iCloud storage). My phone will not let me delete pictures or videos at all. I can select them and “delete” them but they don’t go anywhere. There’s also pictures in my deleted album but I cannot delete them permanently. I am frustrated and don’t know what to do! Has anyone ever had this happen and can offer advice? Please help!!!!