After breaking up, I couldn't help texting my ex-boyfriend and wanted him to change his mobile phone number.

You can't extricate yourself from this indecisive relationship and make the other person and yourself miserable, can you? If this man is worthy of your love and you don't want to let go, then strive for it. When you are together, cherish it. If this man is like that, I advise you not to waste time and feelings. Let it go. Give yourself and each other a chance to live. To find your better feelings. Continue to struggle, will only make yourself more painful.