If you really want to stop the divorce and save your marriage, then you need to convince him that your relationship is worth another try. This is not easy, and it won’t always be possible, but it is the only way to stop the divorce. The divorce can be stopped at any stage before it is finalized, but the earlier it is stopped, the better the chance of a reconciliation, because things may get worse as the divorce proceeds.
The only way to stop the divorce and save your marriage is to convince him to give your marriage the chance that it deserves. However, begging and pleading will not make him come back. That won’t convince him that your relationship deserves another try. It will probably convince him that the divorce is worth a try. He won’t want to be around you when you are acting desperate. That is not how to get him back. So what can you do to stop the divorce?
I know how upset you are, but you need to take control of your emotions if you want to win him back. You need to start acting in the way that attracted him to you in the first place. Try to explain to him, as calmly as you can, that you really want to stop the divorce and save your marriage. Losing control and being hysterical will not make him want to come back. Explain clearly and as unemotionally as you can that you are very sad and hurt, and that you really want to give your marriage another chance. This calm behavior should have a surprising effect on him. Your avoidance of hysterics, pleading, begging or other desperate behavior will have a positive effect on his attitude.
You may wish to suggest marriage counseling as a way to stop the divorce and save your marriage. Explain to him that counseling has worked for millions of couples, and if he is willing, your marriage could be saved. If he agrees to marriage counseling, then this will give you more time to convince him to give your marriage another chance. He can be reminded, in counselling, why he fell in love with you in the first place, and what attracted you to each other. If you can demonstrate to him that you are willing to help put right any issues that arise in counseling, that would help convince him to stop the divorce and save your marriage.
Stopping the divorce, of course, is not the end of the problem. He wanted to divorce you for a reason, and if that is not dealt with then divorce will still remain on the cards. It could even be easier for him to contemplate divorce, having started it previously. So you both will need to meet your problems head on, and continued counseling would probably be a good idea.
To stop the divorce will probably turn out to be the easier step. To save your marriage is going to take hard work on both your parts.