When I break up with my boyfriend, I want to send him a short message, which means that I will get rid of my bad temper and willfulness, understand him, and become mature without him.

Actually, we can't help you much in this matter.

The key is to look at your partner. If he insists on breaking up with you, nothing we can say will help.

You can tell your boyfriend what you think, hoping that he can give you a chance to change, and at the same time ask him to believe you. You will change yourself slowly with time.