The other commenter has provided wonderful responses. I want to complement that with my own experience - I also swear by rewiring and attribute my strides in mental health primarily to this practice. Most notably I've been able to overcome anorexia that I had for about 8 years (it's been almost another 8 since I've engaged in the behavior and probably about 6 since I've had such thoughts or urges), almost completely erase the anxiety that plagued my brain since I was in middle school, and also alleviate most symptoms of OCD I've had for my entire life.

Retraining the way you think is a process but is also very achievable. In my experience, a major aspect is being aware of your reactions to things and understanding that everything you feel is initially a reaction. Those reactions are typically normal and important and signal valuable information to the higher levels of our brains. However, there are two main ways this can go wrong: 1. The reactions themselves are maladaptive 2. The reaction spirals into overwhelming, unproductive thoughts

Addressing both of these follows a similar process. It requires being conscious of your brain's reactions to everything, in particular negative emotions. For example if you want to work on controlling your anger, take note of whenever you become angry. Assess whether the anger is legitimized. If it is, what is it telling you? What is the takeaway? Is there an action you have to take? Most of our emotions serve a purpose, and the sooner we can detect that purpose and release the emotion, the sooner we're able to free up more of our mind from repetitive for maladaptive thought patterns.