The issue here seems to be one of a lack of trust. You may or may not have forgiven the one with whom you were in a relationship for the 5 years. Even if you have completely forgiven, you still may lack trust and this is not a sign of unforgiveness. It is a sign that you know hurt is possible when you commit to others. Forgiveness can help with taking the risk and at the same time your using common sense in the new relationship, along with sincere acts of trustworthiness by the other, should help to slowly create a trust with the new person.
There is a difference between what forgiveness is (it is being good to those who are not good to you) and your motivation to forgive. There is nothing wrong with being good to another person so that you can emotionally heal. Here is a link to one of my essays at the Psychology Today website that gives you more information on this: 9 Purposes for Your Life When You Forgive.
Forgiveness is a moral virtue. All moral virtues (such as justice, patience, kindness, and love-in-service-to-others) are good. Therefore, forgiveness is good. Goodness is not folly. Because forgiveness is part of goodness, it follows that forgiveness cannot be folly.
That said, you may not be ready right now to forgive certain people for certain unjust actions. This does not make you a bad person. Forgiveness does not have the same quality as justice. Certain forms of justice are so important that they are encoded into laws of the state: Do not murder, for example. Forgiveness is not codified into law because it is the person’s choice whether or not to forgive a given person for a given unjust action. So, if you do not want to forgive Hitler for the pain he has caused to you (and he can cause pain to those who were born long after World War II), then you need not do so, and remain a good person.
It is never too late to forgive. You see your father’s mistakes. I think that he sees them, too. You surely have a right to your anger. At the same time, you could give your father a huge gift of mercy and aid your own emotional healing if you have mercy on him and consider forgiveness. It will take a strong will and courage for you to do this. You will know if and when you are ready.
It is normal to feel some anger in the short-term when others act unjustly. It is the long-term anger that can last for decades that can be the problem. That long-term anger can deplete one’s energy and cut into one’s happiness. It is under this circumstance that the unhealthy, long-term anger needs to be addressed and reduced.
It seems to me that if the anger is very intense and includes resentment or even hatred, then, yes, it is harder to forgive. Some people who are fuming with anger cannot even use the word “forgiveness” because it intensifies the anger. At the same time, if a person has deep sorrow, sometimes there is an accompanying lack of energy and the person needs some time to mourn first. At such times, the person needs to be gentle with the self as emotional healing takes place.
We have to make a distinction between what forgiveness is and one important consequence of forgiving, namely being healed of powerfully negative emotions. When we forgive, we offer goodness toward the one who hurt us. The paradox is that we as the forgivers, then, can experience emotional relief. Yet, that is not the end of the story. As you forgive, you begin to know the pathway of forgiveness and now can help others, such as family members, think about and practice forgiving. Your experience might prove to be valuable to those who are new to the process of forgiving.
Yes, the advice is this: When you forgive a person, ask yourself if it is best to let the person know by saying, “I have forgiven you” or whether it is best to show forgiveness in other ways such as a smile or attending to the person’s spoken ideas. The other person, in your case, was not ready to hear the words. I recommend patience and forgiving even for the laughter. Then, try to show forgiveness without using the words “I forgive you.”
I have come to realize that when we forgive, we do not develop a kind of moral amnesia. Instead, we remember in new ways, without the deep pain we experienced at first. We tend to remember the hurtful experiences of our life (such as a broken bone when the adult-person was a child, for example). When we remember injustices in new ways, this helps us avoid being treated badly again in the same way by the same person.
When we forgive, we are saying that certain behaviors are unjust. We separate the person, as possessing inherent worth in spite of that behavior, and the actions, which are considered wrong. So, you can honor your parent as parent, as person, and still make the correct judgement that sometimes even our parents can act inappropriately. In other words, you can forgive and maintain filial piety at the same time.