cheating trauma & moving past it

let me start off w no I did not cheat. I was cheated on by my boyfriend/father of my child. it was about 6 months in & it’ll be our two years in may. i recently got into therapy and i have my first session on tuesday because i have a lot of trauma/trust issues and resentment now but i’m curious... IF YOU STAYED & CHOSE TO FORGIVE YOUR SPOUSE, how did you build trust again? any exercises? certain way of communicating? couples therapy?