I believe that if you faced the judgment and self-hatred, the rest might fall into place. I have two general strategies to suggest, which you could use together.

1. Practise looking at the thoughts like “I’m lazy” and “I hate myself of for being so lazy” and seeing them for the empty things they are. They’re just thoughts. They’re not even yours. They mean nothing. They consist of nothing.
2. Look into the reasons for judging yourself lazy and hating yourself for it. Is there a voice you hear in your head saying these things? Whose voice is it? (Is it a person from your past or a part of yourself you can identify?) Maybe you’re reacting to something you were told or taught very young, which was helpful at the time, but not helpful any more.

Your body wants to conserve energy or it’s afraid of overinvesting energy in practising the piano. If you saw that more clearly, you might more easily identify what to do next.

I stopped studying piano when I realized that I wasn’t prepared to put in the practice needed to develop the raw finger strength and dexterity to play even medium difficulty Bach fugues. I saw what it took and the effort didn’t interest me enough to stick with it. I have invested that practice energy into something else instead and I feel much happier for it. I have a facility for music, but I’m just not that into it as a technician. I have enough to appreciate virtuosity in others and that’s enough for me. Maybe you can find something similar.

Peace.