It is very common to feel depressed after a break up, regardless of who initiated the move.
If your boyfriend or girlfriend is the one who initiated the break up and you still love him or her very much, chances are you will feel the urges to get him or her back immediately.
However, this is not necessary the best move.
First, you are probably too depressed to be able to think very clearly.
Therefore, it is advisable that you do not contact your ex for the time being until you feel much better.
When people are depressed, they tend to make certain mistakes that make them seem desperate and needy.
You certainly do not want to give your ex the impression that you are desperate and needy.
These are very unattractive attribute and will only serve to make you more unattractive in the eye of your ex.
In fact, it can end up pushing your ex further and further away.
For example, you do not want to go around stalking your ex.
Maybe you think our ex is dating someone else.
So, you decided to go to places you think he or she will go to.
And you try to accidentally bump into them.
Well, don't do that kind of things.
Your ex will instantly see through your plot and it will only make your ex more resistant towards you and make the whole situation worse.
Also, you do not want to flood your ex's mobile phone with too many of your text messages.
Neither do you want to flood your ex's email with your email messages.
Doing all these stuffs only serve to irritate your ex further and you are much better off by not doing them altogether.