upsacling removes the grainy texture from my image

Added grain usually looks like digital noise, and that is usually reason for rejection. Designers can easily add grain to the their compositions if that's the look they're going for. 

Upscaling is an Art in itself. The upscaling program needs to create information by interpolating neighbouring pixels. Some upscale programs do a good job with that, but somewhere there is a compromise of what can be done. When you upscale noise, you get countless blurry patches. Or the upscaler denoises the picture first, to get a better base to upscale and preserve the important detail. There is no easy solution.

Upscaling stretches the image. This results in the software trying to feel in the blanks. There is software, such as from Topaz, that use AI to do this. There are also products, such as Photoshop, where you can add grain manually.