With most breakups there is enough confusion without keeping it going by chasing after your ex like he is the only man in the world. I know you are hurt and at times think that if he doesn't answer your text or take you phone calls you will go crazy. But, getting your ex boyfriend back doesn't have to be such a terrible ordeal as most women make it.
You will have a much better chance with the man you love if you show him that you your strength instead of weakness at this time. If he wanted to talk to you, he wouldn't have broken up with you. Instead he would have sat down and calmly discussed what was bothering him, but he just dumped you and walked away. So what makes you think anything has changed?
To get back the man you love, there will have to be changes made and since he broke up with you, it would seem that it is you who will have to make those changes. It takes two to make a relationship work, but only one being dissatisfied can tear a relationship apart. Which should tell you that your ex boyfriend found enough fault with the way things were going to want out.
Your ex boyfriend has faults and I'm sure you could sit down and list them, but he is gone and you want him back. Which means you need to look at yourself and recognize your part in the breakup. However, before you do that, you have to decide if you really want your ex boyfriend back because you love him or is it because you are humiliated at being dumped.
If you decide you still love the guy, then you must do whatever it takes to get him back. Sit down and be honest with yourself and don't deny your part in the breakup. Your boyfriend would not have left you if all of his needs were being met and he was completely satisfied with you. I'm not placing all of the blame on you, but to get your ex back, you will have to change the things that made him unhappy.
Once you face the reasons you boyfriend became disillusioned with you, you can start fixing them. Don't try to do it all at once. Isolate each problem and take it one step at a time. If you gained weight, make plans to lose it, if you were complaining and nagged him, you have to work on being less controlling. If you cheated on him you have to end the affair and make sure it is over for good.
While you are improving yourself, your ex boyfriend may be looking at his own short comings and making some changes too. When you go about things in a sensible way, they seem to work themselves out. If your ex decides he wants you back, he will let you know. However, if it doesn't work out that way, you will be better prepared for a successful relationship with another man. It might be hard to believe at this time, but you can find someone else and have a happy life.