How can I update my product variants without losing image definitions?

Dear sirs.

I have a big problem with updating my products.
For example: I’m selling underwear (bras). I have many variants of one article (different cups, different colors and different sizes). I defined pictures to each color.
When I update product basis (import) those definitions of pictures disappear. This makes me crazy.
Is there any option to avoid this.

I have also normal lingerie shop and one stock for both shops (web and real one). I import products (CSV file) at least two times a day (the major reason is changed of stock quantity, adding new colors …)

What can I do?
Please, help me.

Best regards.
Blaž Rebolj

Can I get to understand you more so we can be on same page and with they I can get to help you more

Please, give me more information.

I would like to assist you more that’s why I asked for more explanation and also do provide me with your website link

https://trgovina-neza.myshopify.com/