iCloud storage doesn't help. Trust me. /5c with 16GB and 0 free space... even with "optimize storage on phone" for photos enabled they still take up all my spa

iCloud storage doesn't help. Trust me. /5c with 16GB and 0 free space... even with "optimize storage on phone" for photos enabled they still take up all my space I have several gigs taken up by whatsapp alone and I do not want to delete my history.