Forgiving can be VERY difficult at the best of times, but how do you forgive the person who murdered your child? How do you forgive the person who imprisoned someone for 20 years as a sex slave? How do you forgive a man who has raped children? These are all very emotive and sensitive questions that need answering in the most delicate manner possible.
Human nature is a varied and wild beast. We think we are above the animals because of our intellect, but we are only above them by one level of existence. We still have to deal with our base instincts, our base emotions, our base attitudes to life in general.
The human realm is still one of Dukkha. We have to battle every day with the suffering caused by our emotions and attachments. These are all left-overs from our animal ancestry, and they take a hell of a lot of training to get them under control. You are not ‘weak’ if you have trouble doing so, you are merely human.
Even the God realm suffers! They have their emotions to deal with. The Divas are just the same. They crave certain sensual pleasures just as we do, so we are not alone. They have emotions to deal with, you only have to look at the Christian God to see wrath, anger, jealousy to name but a few. To forgive someone who has done us a serious wrong is a blessing both for yourself and for the perpetrator of the crime. It may very well take years for you to be able to achieve that state but when you do, the relief is unfathomable. It releases you from anger, hatred, guilt and a host of other emotions. Forgiveness is good for YOU, the other party may benefit a little if you tell them, but the main effect will be on you!
However, you should not beat yourself up about it if you cannot forgive. We are all human, and we are all on different points of the path to liberation. If you really cannot forgive someone, then accept that fact and move on to other practices. Metta meditation would be a good start. Look it up on Google or YouTube, there is plenty of instruction out there. It is the meditative practice of loving-kindness. It engenders a sense of kindness and compassion to ALL sentient beings, so it will help with any forgiveness issues you may be dealing with.
At the end of the day, forgiveness is a very personal issue and not an easy one to solve, so practice, practice and also practice. You will be better off if you succeed so it is worth trying.