Some relationships end on bad terms whereas some end on better terms. No matter how your relationship ends if you're not the one to end it (and sometimes even when you are) you're very likely to end up feeling lost, alone and hurt. There are things you can do that can help make your breakup not feel as harsh as it would if you tried to handle everything on your own.
Create some space between you and your ex. If you're constantly around him, he's not going to be able to miss you. It's likely you won't get your man back. Not to mention, if you're under emotional stress you're not at your best. You're going to make many mistakes that make you look like a fool and sometimes even desperate.
You're allowed to acknowledge your feelings. Bottling your emotions can be just as disastrous as letting them control you because you're likely to explode–figuratively speaking. Part of the breakup and reunite process is to grow from your feelings. By understanding your emotions and working to control them you'll become a stronger person. On the opposite end of the spectrum is to not let your emotions bottle you up. When you let your emotions rule you, you give in to grief and confusion that will only keep you from healing or getting your man back.
If you want your man back, you're going to have to do some changing. Usually a breakup isn't only one person's fault, but if you want something you have to be the one willing to work to get it. Your ex has already said they want to give up but if you work hard to change enough that you become appealing to your ex again your ex is going to see the point in not just giving up.
Most importantly, don't lose yourself. At the moment you're about to crash and burn you need to turn to things that will keep you from hitting rock bottom. These can be any physical activity you like to do or friends and family that care about you. By being physically active you're going to start feeling better about yourself and you'll look better, too. By being socially active with those that love you, you're going to have a support group that's better (and healthier) than turning to devices that can numb your senses.
Getting your man back requires a lot of dedication on your part. You have to be serious and you have to take action. Being passive will only allow your opportunity to pass you by.