You may be thinking that since your boyfriend broke up with you he does not love you anymore, and although that possibility exists, it is very unlikely.
Love is not like a light that can be switched on and off at will, if this is what your relationship was like then it wasn't love it was lust.
Love is more like a raging fire it burns hot and is very difficult to put out, at times the flames can be subdued but the embers are always glowing and can flare back up again if the conditions are right.
The first thing that needs to be done in order to rekindle the flames is to figure out what went wrong, was it some thing you did, was it some thing he did or a combination of both of you.
Once you know what it was you need to address the problem in a civil manner, one of you will need to keep things under control when you finally make contact with each other.
The reason I say "finally make contact" is because immediately after the break up and for about two weeks there should be no contact with your ex boyfriend.
If you do, like most do when the break up first occurs which is, hounding them day and night trying to get them to talk to you, you will only push them further away.
Trust me on this he will probably call you within a week wondering why you did not do the expected such as, the hounding part I mentioned early.
After a short period of time when both of you have had time to calm down and come to your senses, you can set up a meeting, which should be in a public place where there will be other people around, this will help keep the meeting civil.
You should address the problem, which caused the break up, apologize for whatever it was you did wrong, (be sincere) and be prepared to accept all the blame.
Once you reach this step of the first meeting after the break up, the flame is relit now all you need to do, is start nurturing it back into the raging fire, it once was.