Is it normal?

My man’s leaving this week for a couple of months for work.Since he knows his date of leaving,(we talked about it and he told me he’s acting like this cause he’s leaving)he’s kinda in his little world.He is doing his stuff alone all day long and I feel lonely,like I don’t belong anymore to his world,his priorities.He said he’s minding himself to leave.It’s the first time in our young history we have to face it.I’m really taking it personally.Ideas?