For a while in therapy we tried personifying my self hate and giving those thoughts an actual name. In my case that name was Maurice and I do not remember why. That was every time a negative thought happened I could be like "No Maurice, you're an idiot. I won't listen to you."
Unfortunately it turns out Maurice can cite sources.
I don't know if I would say downsides but for me it just didn't work at all. I imagine it works well for loads of people but all it did for me was make me look for more scientific reasons to hate myself. Hence saying that Maurice could cite sources.
Instead of "your art is bad" I would be thinking of every little detail I was doing wrong individually as well as convincing myself that I will never be able to shake those issues. Other stuff did end up helping but that specifically wasn't for me.
(It's from a famous French ad where a kid accuses his goldfish Maurice of eating the chocolate mousse to hide his own mischief. https://m.youtube.com/watch?v=ASc40_mpZjU)