Need different prices and skus for each individual variant

I need these variant options

Fine- Size 4 (3.5mm) ,Size 5 (3.75mm), Size6 (4.0mm) & Size 7 (4.5mm) - $35.50

DK- Size 8 (5.0mm), Size 9 (5.5mm), Size 10 (6.0mm) & Size 11 (8.0mm) - $36.50

Bulky- Size 13 (9.0mm) , Size 15 (10.0mm) , Size 17(12.0mm) & Size 19 (15.0mm) - $37.50

Each specific size also has their own individual SKUs and barcode. For example, Fine Size 4(3.5mm) SKU is KNUS-RW-4 and barcode is 864538000495 while DK Size 8(5.0mm) SKU is KNUS-RW-8 and barcode is 864538000419.

But when I go to add the size variants under DK it is forcing me to lump them in with a connecting size in the Fine variants.

Can you please tell me how to do what I need to do?

My store is https://mytwoladiesknitting.myshopify.com/