When you think about something for the first time, once you find that you want to think the worst, you should immediately cut it off and control the source. This is about considering personal self-control. People with good self-control can find themselves thinking the worst again earlier and stop thinking about it soon. If you can kill bad ideas in the birth canal every time, you will gradually get rid of this habit. This is the same as when we weaned the baby. If you don't smoke, you don't want to smoke again.
But if every time you find yourself thinking something bad again, unfortunately, you have finished thinking it, then you should also refute what you think. It's like a debate, with more rational ideas to overthrow your bad settings one by one. Then think about it better. If you can, you'd better write down this wonderful idea and meet it later to see how much your good idea has been realized. Recorded ideas can easily arouse your interest, and if they are realized and supported by reality, they will also make you look at good ideas and think more. As you know, people's energy is limited. Once your attention is attracted by good ideas and put into them, you will naturally think less of bad ones.
In fact, the most important thing is to cultivate your positive attitude towards life. After all, this is the embodiment of the outlook on life. You should get in touch with more positive things, learn from people who live actively and read more warm books. Not only will it warm your life, but your outlook on life will become more and more "warm".
I am like this now: if I think the worst, I will immediately clean up the whole house, or eat half a bitter gourd (I hate bitter gourd) to punish myself. This is psychological aversion to stimulation. If you think about it, you will immediately show what you hate, then you will not think about these things in the future, and it will be very uncomfortable to think about it. If you just think about it, you can't correct it; If it makes us feel uncomfortable and forced, then we can't wait to correct it immediately.
I hope these methods are also useful to you and can encourage you. I hope we can constantly overcome our bad habits, think positively when thinking about things, and don't always fall into pessimism and disappointment. I hope we can all do it.