Wow! Thank you all so much for your replies - I am truly grateful to each and every one of you.
We talked until the small hours this morning - he told me things he's never mentioned before, as he was ashamed, it explained a lot. How he was beaten up (a lot, and badly) at school, even witnessed by his father, who berated him for not fighting back! He does struggle with self esteem (which is pretty much zero) but will do anything to help anyone, often at inconvenience to himself, but I suppose that's his way of making sure people like him?
I didn't think about how much men identify with their job/work, which I think is the case with him. He truly was mortified and understands the reasons why they got rid of him (but not the witch hunt that went on, according to his friend who still works there, and is horrified at how H has been treated).
He has signed up for some online counselling for his childhood issues - he says if he felt better about himself he might have felt more capable of challenging the work issues as they were ongoing, and would have felt braver about telling me what was going on. The counsellor will be ringing him tomorrow to see what he needs. He understands what he needs to do, and that he's the only one that can do it.
I have no worries about him taking my pension or money from the house etc - the reason for his previous money difficulties was a poorly paid job, he was still living at home, his father became very unwell and had a very small pension - so H stepped in and tried to provide for them. When I sorted that out for him, he had all his bank statements - no frivolous spending but a lot of stuff for his parents, to make their lives easier, and bills etc. His hours were also cut, which escalated matters.
He has also suggested marriage counselling if I think it would help - I'm certainly considering it.
He's also sent off for 40 jobs since the weekend and had several agencies reply to him - he has showed me everything and said he understands I have lost trust in him and why, and that he will do everything he can to regain it - although he knows its not going to happen in 5 minutes, if at all.
I'm still considering the holiday - yesterday I would have said it wasn't safe for me to be confined in the same room with him (for him, not me - he is not and would never be violent towards me!) I really need a holiday, and he told me today that he's arranged a class for me near the holiday home in a hobby that I like - a surprise for my birthday. He said he understands if I don't want to go, or go on my own, or stay at home, no pressure from him, it's whatever I want to do.
So, all in all, I think he realises he needs to make changes in his attitude at work, and to address problems in his childhood, and to work hard on regaining my trust. He said what an idiot he's been in keeping his dismissal from me, and that I could probably have helped him if he had mentioned to me when things started going wrong. He admitted he's not been happy there for about 3 years (company taken over, management changes, 50% staff level, pressurised work, shift changes so that allowances worth £5000 a year were removed) but didn't feel brave enough to look for another job better the devil you know, I think. Now that he has no choice, he's really throwing himself into the job hinting it and seems 100% happier in himself.
Thank you once again, lovely Gransnetters! I think I can see a future for us, which is a huge improvement on last weekend.