Try Metta meditation. I personally like Ajahn Brahm's method of Metta meditation, focusing first on people we can easily cultivate Metta towards and gradually expanding it to include everyone, which is roughly as follows:-
1. Imagine in as much detail as possible, a small, helpless, emaciated creature. (maybe a dog or cat, whatever it is that you like) Preferably this creature is purely imaginary and doesn't represent a real being.
2. Imagine that you are maintaining eye-contact with this kitten or puppy or whatever it is that you have chosen and are sending it all of your Metta. At this stage you can think "Dear kitten (etc), I know that you have had a difficult life, this short time you have been alive all you have known is neglect, betrayal, cold, hunger and thirst. I will look after you, I will care for you, you are safe with me."
3. Slowly reach out and pick up this being and hold it to your chest to keep it warm until you feel the warm tingly physical sensations around your chest which is the Metta that you have cultivated.
4. Now focus on a real person, someone who you are close to, someone who you have a good relationship with.
5. Send them some of the Metta that you have cultivated.
6. Focus on a neutral person, someone like a storeperson or a neighbour, who you see often but have neither positive nor negative feelings towards.
7. Send them some of the Metta that you have cultivated.
8. Focus on an "enemy", in your case it might be a rapist or murderer you have heard about in the news.
9. Send them some of the Metta that you have cultivated.
10. Send Metta to your whole suburb, then your city, then your state, your country until you can imagine the whole world in a glowing ball of Metta.
11. Lastly, bring some of it back to your own heart for later use.
I hope this helps
Four types of letting go:
1) Giving; expecting nothing back in return
2) Throwing things away
3) Contentment; wanting to be here, not wanting to be anywhere else
4) "Teflon Mind"; having a mind which doesn't accumulate things
- Ajahn Brahm