My ex-husband hasn't contacted me for a long time. I really want to break up with him, but I just can't forget his phone number and can't help sending him a text message.

You can make up your mind to blacken his number first, so that when you want to send him a message in the future, you need to blacklist his number, which will give you more time to hesitate and calm down, and maybe you can hold back from sending a message.

Then, every time I miss him, I should deliberately divert my attention, such as doing sports, watching movies or chasing variety shows, or going out with friends, or busy with work and learning something new. In short, you should keep yourself busy thinking about him, and don't give yourself time and space. After such a long time, your life will gradually enrich, and one day you will forget him.