What should I do about my anger towards the perpetrator?

First, let me tell you that feeling anger towards someone who has hurt you is a very natural and valid reaction.
There is no need to blame yourself or feel ashamed of your feelings, thinking, "I shouldn't be feeling this way" or "I should forgive the other person." The fact that you feel anger speaks to the fact that you have been hurt.

Sometimes, anger can come over you in waves so strong that it's hard to process. Anger is a natural response to injustice and unfairness, especially when your important boundaries and dignity are violated.
If you are aware of your anger, it means that you are trying to feel and value your own emotions. Your emotions are born to protect you. Please don't forget that.

You don't have to force yourself to forgive, or try to dismiss or minimize your anger, but it's also important to find ways to gradually let it out in a way that doesn't cause you more pain or burden you with shame or guilt.

Some people find it supportive to have someone they can trust listen to them without being judged or rejected. This can be a friend, family member, counselor, trauma care professional, or anyone else. Putting your feelings into words and entrusting them to someone who will simply listen can be an important step in giving your anger and pain a place to live.

For others, writing in a journal, expressing themselves through art or music, or gently moving their body by taking a walk can help them safely release the emotions that have built up inside them. What works for each person is different, so it's okay to choose a method that feels even slightly comfortable to you.

Anger is not an emotion that needs to be "turned off" in order for trauma to heal. It is an important part of your recovery process that should be acknowledged and respected. With time and support, anger often changes form, and even if it doesn't go away completely, it may become more manageable and less overwhelming.

Furthermore, in the process of recovering from such betrayal or deep hurt, it is not uncommon for other emotions, such as sadness or fear, to quietly exist beneath the anger. These are all natural reactions, evidence that the mind and body are responding to the deep wounds.
If you feel that it is too difficult to deal with on your own, one important option is to seek professional support, such as a counselor who understands trauma.

You deserve support to work through these strong emotions without hurting anyone else, and most importantly, without hurting yourself.

Any page is fine.
I hope that you can gently give yourself permission to feel that way, treat yourself kindly, and move forward little by little, at your own pace.