It is only natural that you want to hurt your ex as much as he/she has hurt you! But playing "Tit for tat" is not going to help the situation, especially if you have come to realize that you can't do without your ex - even though you were unceremoniously dumped!!! Move on ahead and do your best to make your ex realize the mistake he/she made in dumping you.
  Forgive and forget.
There is no way you are going to be able to reconcile with your ex if you are still hurting and mad at your ex for the way he/she treated you.
You have to let bygones be bygones and move forward.
The fact that you still love him/her shows that you are actually ready to forgive.
That's really good but the real part of forgiving is the forgetting! You have to forget the hurt so that you can start afresh.
Bitterness will fall away from your aching heart when you have learnt to let go of past hurt!   Be magnanimous.
Once you have decided to forgive your ex's treatment of you, you should go all out to prove to him/her that you do not hold a record of the bad things he/she said and did.
Once your ex realizes that you truly have a forgiving heart and nature, he/she will automatically learn to relax and be natural around you again, without feelings of guilt.
This will make it easier to restart the relationship.
  Recapture his/her interest.
Your ex should be stunned at the new creation that you have turned into.
If he/she sees you looking better and behaving better than ever, he/she is going to regret dumping you for someone else.
Go all out to prove to your ex that what he/she did was wrong without actually mouthing the words! The reality of the situation is bound to sink in sooner or later and your ex will want to have you back in his/her life again.