1. Write down everything that's hurting you in your life... thoughts about ex girl/boyfriend... memories of your friends... things your siblings said to you.
2. Collect anything you might find related to these memories - pictures, letters, phone numbers - anything that you've written about her/him, about your friends, or events that hurt you in your diary, online, email, social media. Collect all of it.
3. Put all of this together in a metal trash can - do this outside your house.
4. Then light all the stuff on fire - (if you're afraid of fire, then just rip up the paper and throw all this in the trash or flush down in the toilet)
5. When you're burning these past hurtful memories say out to your self, "Thank you for what you've taught me - I now release you to the universe!"
6. Delete all her/his pictures, phone number etc - and then say in your heart - "Thank you _____ (her/his name) for everything you've taught me. I release you to the universe. Have a great life."
If you don't do this - you will keep focusing on her/him and the things she's doing and won't allow yourself to feel love from anyone else. You'll be stuck in a dangerous downward spiral in your life and wont be able to get out of this.
But by doing this you will release all the pent up energy inside you. Release her/him and the hurt inside you, so you can feel love in your life.