Freaked out husband

[illuster]

My husband doesn’t know how to deal with emotional issues in our relationship. (Maybe I’m not putting that into words in the right way so I’ll try and explain through some examples...)
He’s a very laid-back and easy going guy but maybe that’s just the way for him not to deal with emotions...

For instance, he has an elaborate hobby and puts a lot of time and energy into it.
When we talked about this, I asked him why he felt the need to be away from home (me) so much and spend so much time at this other place (for his hobby). He said he isn’t running away from me. It’s not escapism, he just feels good at that other place and enjoys what he’s doing there.
I told him I thought it was because he gets a lot of validation from everybody there. They are constantly telling him (and me) how wonderful and talented he is. (And getting ‘addicted‘ to that is a form of escapism, right?)

He didn’t agree with me at that time. But a few months later we were talking to a mutual friend and he said the reason he spends so much time on his hobby was because he gets so much validation from the other people involved... I confronted him (in a light-hearted way) and told him he didn’t agree with me when I had made that exact point. He said he had thought about it and realized I was right...
Nice to hear but it took him months to figure this out!

He can deal with conflicts in his professional life and in his hobby. He doesn’t shy away from a discussion and is a very good listener. He’s very good at giving advice, a little too good at times...

But...
Whenever I try to talk to him about something that is bothering me in our relationship, he listens to what I say only he won’t join in. Now I’m not the shouting kind, I try not to attack him, push him into a corner or make him take all the blame.
But whenever I address something he reacts as if I’m pointing a gun at him:
He withdraws completely and I can see he’s thinking very hard. (you know how peoples eyes wander around, when they are desperately trying to make up a lie and have to think really fast) It looks like that only his thoughts are just going around in circles and he can’t seem to process them. So he just sits there looking completely freaked out and I can’t reach him anymore. He has told me once all he is thinking then is things like “I’m a failure, I’m hurting her, I’m making her unhappy,...”

It’s very frustrating and I get sooo angry at him. Because I get no feedback whatsoever and all I’m trying to do is start a constructive conversation where we can both figure out how to deal with a situation. I try to stay calm but my frustration is probably very obvious to him.

Recently I’ve realized that when I’ve had my say, he seems to think the issue is resolved...
But that way, I’m just venting frustrations and everything stays the same...

It’s not like we’re having issues at the moment. Everything is going very well. Yes, I know how that sounds after what I just wrote...
I’m just worried that someday, this might start to be a real problem... Any advice is welcome!