You should both speak your heart AND let it go. I don’t know what you went through, but I can understand pain, especially when you feel like you’ve been keeping that pain bottled up. You should speak it. Not to her, because I think you should, at the very least, give you both some space from each other. But it might help to talk to a friend or family member or counselor. In the past, I have written down my anger and feelings of ill will towards others, and burned the pages.
Keeping all that pain and anger inside of you is like a poison for your soul. Find a way to express it in a healthy way (like journaling, talking to a friend, meditating about it, talking to a counselor, writing poetry or music, etc.,) and let it go. An adaption of the Christian Serenity Prayer that I like is, I have the courage to change what you can, I have the serenity to accept what you cannot change, and I am searching for the wisdom to know the difference.