Go to edit profile,of the left go to 'friends and family' , then when you see small thumbnails of your friends there is a clickable option (yours is probably a gloge suggesting your friend list in public), click it to make 'friends only' or 'custom-only me' whatever you like
Go to the small downward arrow on top right, click privacy settings-how to connect-who can look up your profile by name and info- make it friends or friends of friends.