You are doing the right thing by taking your kids to therapy. Witnessing what they did (dad's attempt) is too much for any child (or adult).
While adults can work through situations or 'plow through them' if they have to, children cannot. You are giving them close guidance which is what they need. While therapy can address that trauma they experienced.
And you are doing a great job btw. Even the best mom's in the world don't have all the answers. Your family will get through this.