Thanks for your reply, Patron. It's very significant that it's developed since traumatic events at work. That you've recovered from "worse" doesn't mean anything in the greater scheme of things, I'm afraid, as different abuses affect individuals in different ways.
I had a major breakdown in response to abuses at work and home. I suspect people who've known me since before it happened are bewildered by the radical changes in me, not for the better in outward terms. I was diagnosed with PTSD and still have anxiety disorder & depression (we don't do CPTSD - complex ptsd - in this country, but one of you might want to read a little about it).
In a nutshell, bullies abuse you for doing what you do well. When they succeed in breaking your confidence, the psychological effect can be to 'prove' that being your best self causes pain. Overall, it wrecks your understanding of yourself and leaves you horribly afraid to be yourself. Nasty stuff.
I don't know how much of all this you've discussed with DH or how aware he is of his changes. I'd certainly say it's worth his doing some reading around psychological trauma and bullying; it's also worth googling "psychological injury" as that's what it is.
He may need support from you to regain his confidence, in little steps. He may also benefit from antidepressants and/or talking therapy. It might not work. You're not responsible for his recovery so, if were to all get too much for you long term, you'd be justified in calling time. Just for now, though, I thought it's probably worthwhile highlighting the link to you and recommending some supportive confidence-building.
Wishing you both the best :)