Your inlaws sound quite a bit like my former ones. Hey, I hear ya on the photos. My xh's were like that as well.
I came from a very well rounded family whereby everyone looks out for one another and no matter how much we agree or disagree, we listen and validate one another.
It's just a different world from what we are use to.
BTW, did your mechanic say exactly what the problem is? Could it be a faulty computer chip? Sometimes, they cause that stupid light to come on too. Another thing to beam up that light is a dirty air filter.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.