Open a Finder window. From the menu bar click Go > Go to Folder
Type or copy / paste the following:
Click Go then move the Cache.db file to the Trash.
Quit and relaunch Safari to test.
BTW, if you enable the Develop menu you can empty the Safari cache easily instead of having to go through your user library.
From the Safari menu bar click Safari > Preferences then select the Advanced tab.
Select: Show Develop menu in menu bar
Then from the Safari menu bar top of your screen, click Develop > Empty Caches