@farhanqedri,
Why in the world would this make you detached from the older one?
Who's the adult here?
Wait a minute, adults. You say both of you are detaching. Seriously?
Two adults are detaching themselves from a 4 year old because his world has been turned upside down? Because he's asking questions so that he can make some sense of it all? To want reassurance that his mother and father still care for and will take care of him?
Your son has a job, being your kid. It's all he knows.
If you or your husband showed up at work, and some stranger was sitting at your desk, demanding and getting all the attention from co-workers, superiors and even complete strangers, I guess you'd be asking what was going on, and be pretty worried you no longer have a place.