Can ACT help me with trauma

It's really hard to know how detailed and graphic I should be here but because I want to receive helpful answers to my specific situation, I will provide some details. Trigger warning: SA, Narcissistic abuse, child abuse, violence

I was abused by my older sister who is 6 years my senior. I recently got a divorce and live with my parents on their large ranch. That said, my sister is coming here to visit my dad for the first time in 5 years. I have not seen her in about 7 years. Usually, she only comes around when she wants something from my dad but maybe this time will be different. Regardless, the potential of seeing my sister has been very triggering for me. Today, I discovered I have trauma amnesia, I was discussing my sister with my step mom (who is wonderful, unbiased and charitable in how she views people, just to be clear) and she recalled an event that happened which I totally forgot about where my sister had a horrible temper-tantrum because I walked away from a pot of water that I was trying to bring to a boil when I was 19. She came at me with a butcher knife and was screaming at the top of her lungs, berating me. She told my step-mom she was worried after that incident because her boyfriend saw her lose her shit and she was scared he would break up with her. When we were children, she gave me a concussion, sexually abused me for a year and would not only let other kids bully me, but would actually join with them. My sister now plays the victim and acts like nothing is ever her fault, not just in our relationship but in every facet of her life. She was a drug addict and alcoholic for a decade and that was very painful for my parents.

I'm attempting to give you context to truly convey how difficult this is for me.

Since earlier today when I had break-though memories about things I had totally blacked out that my sister had done, I am now here grappling with very intense feelings.

Can ACT help me with my trauma?