It’s one thing if you decide to break up with your partner, but it’s a totally different story if your partner decides to break up with you. No matter what you do, do not beg or plead. If your partner has decided to break up, begging or pleading will not fix anything. Even if he or she decides to get back with you because of your pleas, that will only probably mean troubled times ahead. Who knows what tomorrow brings anyway?
The best thing that you can do is take it gracefully and try to move on. Easier said than done, really, but remember that you are not alone in this experience. Countless other people have gone through the same thing and moved on eventually.