> I find it particularly soul-crushing because I do have things that I consciously want to do during that time, like write music and film short films, but those things take effort and commitment, so instead I spend night after night doomscrolling Twitter/Reddit/YouTube/HN.

The things that you want to do might be too difficult to begin. Some part of your brain doesn't know that you can write music or make films successfully enough to gain any reward. The mental hurdle is very big if you just stare at a blank sheet music.

Instead, start with something smaller and more structured. Take some lessons, for instance, and do assignments which you know will lead to some form of product.