Every painting has an ugly middle stage. Artists who quit there never find out what it becomes.

There is a point in most work where it looks worse than when you started, and this is a stage rather than a signal. The old thing has been broken up and the new thing has not resolved, so what you are looking at is genuinely bad, and believing it will stay bad is the most common reason people stop.

Recognise the stage when you are in it and make a rule about not deciding anything there. No abandoning, no starting over, no showing it to anyone. You cannot judge a middle by how it looks.