Another approach is to avoid reassurance and cheerleading.
He may see this as downplaying his emotions & invalidating
Try to validate the emotion. What does he feel? Sad, angry, disappointed, whatever.
Pinpoint the emotion and simply say 'I understand that you feel 'sad/angry/xyz' about xyz'. Leave it there. Don't bring your feelings into it for now, he clearly isn't ready to take them on board. Find somewhere else to get them heard. Write them down in a diary. See a counsellor. For now, don't put them on him.
Nothing more & no cheerleading and down-playing.
Leave him to think about it.
As needed, re-validate. Don't get your own emotions involved. Don't 'reassure' or explain how you feel for now.
Focus on dealing your own feelings without him for now
That is recognising them, as needed expressing them. This is part of your Self Care
(This process will test you and you will become stronger as a result)
INFO ON FEELINGS:
The four prime emotions of fear, anger, grief and joy & these give most people lots of trouble, both in having them, dealing with them and communicating about them.
You can visualised your emotions as being kept in a POT
The Pot is real, not imaginary. You have one. I have one. It is where a person stores all the unexpressed feelings or emotions. Physically the Pot is the muscular structure of your body. The way I see it, everytime you do not express an appropriate emotion or an appropriate level of energy, your muscles bunch up and get tense somewhere in your body. You have to. These muscles stay tense for a long time. They may stay that way for the rest of your life.
If you come from a family like many, which discouraged all expression of feelings, all your Anger, Sadness and Joy may have found its way into your POT, and still be sitting there. This is why people sometimes burst into tears when someone gives them a massage. The POT was opened for a moment.
Fear: from the point of view of energy, a constrictive or contracting emotion. Fear makes a person hold in (like your husband is doing). Talk about your fears with a safe person to address them. Talk to a counsellor.
Anger, Sadness, Joy needed to be Safely expressed
Anger - punch a punchball as needed. Move your body.
Sadness - cry deeply at films, songs, whatever as needed . Talk to a counsellor.
Joy - laugh and run around
Don't: Numb Out (all the addictions: alcohol, drugs, religion, chocolate, french fries, sex, TV, etc. These are all based on the idea that “if I do this thing I won’t feel my feelings.” )
Read the four part article on emotions:
https://www.alturtle.com/archives/236