Macro photography with rings and reverse lens

For macro photos I try to use extension rings or reverse lenses with my Panasonic gx9 camera. I have a 12-60 lens. When I deal with any of the methods to take a photo, I can focus only when I use the narrowest ring (7 mm) and only when the lens touches or almost touches the object and then casts a shadow, so I don't get a very pretty photo and dark Should I use a different lens or is there another solution?
Thank you
Shlomo