This is covered in a lot or depression literature, where you need to literally rewire your brain to defeat the attempt to reach homeostasis, which has become a depressed state. Little positive actions and thoughts that eventually rewire the neural pathways and create new ones little by little. If you want to learn more about that, the technical side made very understandable by a psychologist and neuroscientist who specializes in depression and anxiety, you should check out “The Upward Spiral”. It’s really good and i highly recommend it. It has helped me start the healing and coping process.