Constantly badgering him and telling him you cannot live with out him, will only push him away.
Lead him on a chase the same as you did when you first met him.
By showing him you can have a life without him, he will want you again and he will be back for good.
During this time of solving the problem of the breakup, do not try to contact your ex at all.
Once you think you have found the problem, work on ways to fix it.
What most women fail to realize after a breakup, is how sensitive men can be.
You might think that something you just said or did caused him to say he needed space.
That might have been because you had become too available and he took you for granted.
When that happens, men become bored and start looking for a new challenge.
When you have it fixed, do not think you can just call him and tell him what you have done and it make him want you again. But if you cannot call him, how are you going to show him? So get dressed and style your hair his favorite way. Act happy and confident, but completely ignore him.
Then get some friends together and go out and find him. Do not let him get too near you, let him get a good look at you and then leave. This will make him think you no longer want him and he will be challenged to get you back.
Something must have been bothering him to make him do that.