Getting good quality Film Grain on Youtube

[OloffMusic]

Hello guys, first time poster here. I've been working on a video with some artificial noise and film grain added, which obviously looks great on it's own but absolutely horrible on youtube.

I read that you can upscale footage to 4k, however when i do this it looks awful (I've created a new 4k sequence, copy-pasted my original sequence in there, selected all clips and clicked 'scale to frame size', and then exported it as a 4k video with 40/60 bitrate)

I'd really like to know if anybody has any tips on making this grain look better because at the moment it's awful, and also if I'm doing something wrong with the 4k upload?

Thanks