Don't beg him. If you have pleaded with him to give you another chance or reconsider his decision but he hasn't bowed to it, don't beg again. Not only will it aggravate the situation, but it will also erode your self-esteem and dignity.
You don't want to fall into pieces never to heal and recover from the breakup. You don't want to lead a life of misery, a person who has no hope for the future and helpless to move on with her life.
It's possible to mend relationships that have failed. However, knowing which failed relationship will work out again is difficult. There are some factors that can make a failed relationship never work out again.
A healthy mental step you can take is not to contact him for one month. It will be difficult for the pain you feel but it's a step that will assist you in not falling in a pit of despair.
The two weeks will enable you to think about the failed relationship, where it went wrong, what could have been done to save the relationship, and what to do if there is no hope of ever reuniting with your ex.
Some failed relationships don't work out again because the partners didn't take time to heal and recover from the breakup. This is especially the case with relationships that ended on a sour note.
Before you employ the no contact rule, exercise limited contact. In this case, you don't contact your ex for a week. After not contacting your ex for a week, call or text him. Don't be desperate. Let him know if there is anything you did wrong, you ask for forgiveness. If there is any way to amend the failed relationship, you're ready to do it. If he doesn't agree or insists he doesn't want to get back with you, employ the no contact rule. Remember, during the one week of not contacting him, arm your mind with the knowledge things might turn out better or not. If they don't turn out better, you will not fall into pieces. You will accept his decision and move on with no contact rule.
You can read the following articles I wrote to know more about no contact rule and how to heal and recover from a breakup:
1. What Are The Rules and Benefits of No Contact Rule After a Breakup?
2. Steps to Healing and Recovery from the Breakup