Son grieving

I am absolutely heart broken at losing my husband 5 months ago but I am trying to get on with it best I can but I am heartbroken for my 34 year old son who is really struggling to come to terms with his dad’s death and I am concerned.
I have just been to visit him for 5 days and we chatted about our loss .
My Son is in the armed forces and he really thinks that there’s no one to talk to there and he dosent talk to his wife much it’s like he goes to work comes home draw the curtains while it’s still day light and shuts out every one apart from me.

His marriage is struggling a little because of this but I don’t know what to say to him or do for him I have given him all the advice I can but I hate seeing him so upset and unhappy.
He misses his dad dearly we both feel really let down because as well as losing his dad my husband we are now having to cope with a legal battle for negligence.

We both keep thinking his dad will walk back through the front door any second the grief is unbearable at times.

How are you doing Emily?