Basically the problem with turning hobbies into hustles is the addition of uninteresting (and sometimes frustrating) additional work that comes with managing time and caring about customer satisfaction. The extra work can take all the fun out of it.
Feeling the need to be constantly "productive" is, I think, really a separate issue.
I also differentiate between wanting to do something vs wanting to have done something. It's easy to want to have written a novel, to have learned to play piano, or to have painted something. But if you don't enjoy the process (the actual writing, the practicing, etc), then you may just be torturing yourself for the sake of self-image. Find something enjoyable in the actual process and you won't need to force yourself so much, you'll gravitate toward it naturally for its own sake, and you won't feel guilty if you decide to just watch TV or phone scroll instead. (Plenty of books and articles out there on forming new habits.)
Feeling the need to be constantly "productive" is, I think, really a separate issue.
I also differentiate between wanting to do something vs wanting to have done something. It's easy to want to have written a novel, to have learned to play piano, or to have painted something. But if you don't enjoy the process (the actual writing, the practicing, etc), then you may just be torturing yourself for the sake of self-image. Find something enjoyable in the actual process and you won't need to force yourself so much, you'll gravitate toward it naturally for its own sake, and you won't feel guilty if you decide to just watch TV or phone scroll instead. (Plenty of books and articles out there on forming new habits.)