From your Safari menu bar top of your screen click Safari > Preferences then select the Privacy tab.
Click: Remove All Website Data < removes cookies
Now open the Finder. From the Finder menu bar, (top of your screen), click Go > Go to Folder
Type this exactly as you see it here: ~/LIbrary/Caches/com.apple.Safari/Cache.db
Click Go the move the Cache.db file to the Trash.
Quit then relaunch Safari to test.