It's good that you've read some of Barker's other books---you won't be put off by the beginning, which is very dark.
All the ones of his I've read are like that; they can be horrifying to start, but have beauty at the end. Similar to some of Dean Koontz's work.
Very perceptive of you to pick up on Luka's unfamiliarity with English! You're a good mom, working with him and reassuring him. No wonder he's responded the way he has 😉
It's interesting how some people see the patterns and others don't. The way my brother and I turned out is the same way my dad and his sister turned out. Their father was very physically abusive. Dad was a cold bastard, abusive in his own way, but his sister was warm and loving. I don't know if she could have articulated it, but somehow, she was the opposite of her dad and brother, like me.
My husband's family is also extremely dysfunctional, on both sides, going back at least a couple generations. My husband and his two sisters all show the patterns their parents exhibited, and none of the three of them has the first clue there even IS a pattern. In turn, the pattern has passed to his sisters' kids and is starting in the youngest generation. It's amazing to me that no one has caught on by now.
As you say, it takes a very deliberate choice to break the pattern. Also, a lifetime of work.
We DO have a lot in common. Unfortunately, there are WAY too many others like us.