In your case, it will be possible to show the stock status for the configurable attribute option. Because your products have only one attribute. And its possible to grey out the not available options.
But if you have more than one configurable attribute (e.q. Product Short: Size and Color), this is not so simple. It's not possible to show the quote status in the attribute option, because the attribute option is not a product. You need a matrix table to show the stock status of configurable products in a glace. There are few modules for this use case. But i think, these extension will not solve your problem, because you want to show the stock status at a glance in the category page.
I think, you will not find a module for this use case. But as developer, i know, that its possible to solve this specific use case. But you wrote, that you are not good in coding. Maybe this is not an option for you. But if you like the challange, have a look at this file: vendor/magento/module-swatches/view/base/web/js/swatch-renderer.js
Copy the file to app/design/frontend/{VendorName}/{themeName}/Magento_Swatches/web/js/swatch-renderer.js and have a look to the _UpdatePrice method or have a look to your module, you already use. maybe there is a way to add the required javascript code.
Maybe there is a much easier solution for your case with a modul? Let me know!