When we lose something we love and want, we go crazy to get it back.
Now that may not be the best thing for you to do to win your ex back, since when you freak out, you may also come across as very desperate.
So the best thing you can do before anything else right now, is simply take a deep breath, calm down, and realize that you can in fact get your ex back.
OK, now are you ready? Here is how you can pull your ex back in just days...
Convince your ex to forgive you- You can actually do this! First of all, to do this, you must admit your mistakes and apologize.
Next, you should express that you understand what your ex is going through, and that you know the pain you have caused him/her from your mistakes.
Lastly, do not expect anything from your ex, and tell your ex that you understand if he/she doesn't want to forgive you.
Since you are giving it as a choice, and also are expressing that you understand how they feel (instead of just saying sorry for your own benefit), he/she will be more convinced to forgive you.
Make your ex realize that he/she needs you- The only way you can do this is by literally ignoring your ex afterward.
You must cut off all contact, and that means no more phone calls, SMS's, emails etc! Be strong here, because the minute you stop making yourself easily available, will be the instant that your ex stops taking you for granted.
As an added bonus, this also gives your ex space so that he/she can finally have time to miss you.
Finally, he/she will feel rejected by your sudden lack of attention, and will seek your time and affection even more now.