How to deal with sexually abuisve mom ?

My mom was s*xually absuive

It's going to be holidays soon and I will have to go back to home for 2 weeks . I am really anxious and overwhelmed from it because my mom was sexually abusive towards me as a kid & teenager. Please tell me how do I calm down myself. I am feeling horrible & want some support .

And yes I can't avoid going back due to some situation.