There was a time when the two of you were so much in love. Everything seemed to be going great, but then you split apart. Maybe both of you were glad to be rid of one another, or maybe you wanted to stay together. Whatever the case may be, all you know is that right now you're saying, "I'm still in love but my ex isn't." If so, then there is no need to feel alone. Lots of people have been in the same situation. And some of those same people worked things out and have figured out ways to make you feel better if you're in the same situation.
You should know that it's okay to want to work things out with your ex, but don't just dive into it head first. Before you do anything else, you need to get to the root of your feelings. Do you really love your ex, or is it just the idea of being in love? How did they make you feel when you were together? Are you trying to change them, or are you willing to love for who they really are? You have to be honest when answering these questions. If you happen to find you don't love your ex as much as you thought, that's okay.
The other thing you have to try to figure out is if your ex may have any feelings for you at all. While you may be saying, "I'm still in love but my ex isn't" there isn't any way to know that for sure. Even if your ex said they don't love when you broke up, there is always a chance that they have changed their minds. Granted, their feelings may not be as deep as yours, but any hint that they still care can be taken as a positive sign.
On the other hand, the questions you are asking may only strengthen your suspicions. If that's the case, then you have a choice to make. You have to decide if you're willing to do whatever it takes to get your ex to love you again. That may sound like an impossible task, but it can be done if you go about it the right way.
Whatever you do, don't try to convince your ex to love you. for now, you need to give them some time and space to be alone. After all, they say absence makes the heart grow fonder for a reason. Don't contact them for a while; no phone calls, no emails or text messages, and no bumping into them "accidentally". The secret isn't to make them love you, but to let them convince themselves to love you again. Giving them time is only the first step.
You should also look into other ways of patching things up. That way "I'm still in love but my ex isn't" will soon turn into "I'm still in love and so is my ex."
Hope that helps :)