Balena etcher changing my sd card of 400gb to 50mb every time i etch an image..and I am fixing the disk partition in disk management also.

Hi I am having issues…I have deleted all partitions of my sd card with disk management and making a single partition but every time I try to ‘etch’ an image the sd card goes to 50mb from 400gb? What is going on??? I tried for like 10 times… please help me because i am really getting annoyed and frustrated.