I know unforgiveness is unhealthy for one's emotional state. But I'm scared to forgive a certain toxic person because that may lead to me letting my guards down. I have forgiven her many times in the past and that led to me letting my guard down and opening the door to her damage. (It would be easier to let go if I never had to see her again but that's not a choice...although I did distance myself significantly).

I feel like holding onto what she did to me in the past is only way for me to keep reminding myself to be on guard. If I may use that analogy, it's like holding onto a memory of falling down into a hole, so that I am constantly conscious of the hole to never fall into it again.

How do you forgive but not forget to maintain boundaries?