Hi OP, I was checking back on this thread to see how you are.
Its good news that your DP has agreed to go to the doctors - that's a great step. I would maybe recommend that you go in to the appointment with him if you can? It's very hard to be clear and concise when you're wading through treacle; it will be easier for you to 'speak' for him somewhat; although most GPs should recognise that the mere fact your DP is there for that kind of appointment indicates that there is a problem, but not all GPs are brilliant - you may need to push (I hope not). There is a close link between anxiety and depression.. although your DH may not appear 'depressed', his stress levels could have tipped him in to an 'anxious' state, which can be well treated very similarly..
Another suggestion: Does your DP have Private Health cover through work? If so, he should ask the GP for a referral to a counsellor. I (believe) that the GP will refer to a psychiatrist first, who will assess what sort of counsellor will be most appropriate (at least, that's my experience).
That was an absolutely brilliant point for me, because when 'spilling' all to the psychiatrist during the assessment, one of his responses was 'well, is it any wonder you feel under so much pressure', which made me feel part normal again! They see thousands and thousands of competent, educated people with similar symptoms - you and your DH are so not alone x
The other thing that helped me, was my DH's behaviour; He was so, so supportive, but didn't let me 'wallow'. When the stress and anxiety was getting very bad from work, and I was really starting to lose confidence, it started to spill into home life; not wanting to go out with friends, not wanting to help out at things I'd previously taken in my stride, overly anxious about everything... my DH was supportive but maintained common sense.. "Come on, you're not staying in, you'll be fine, you're great at this, etc. etc.., you're not sitting in worrying about it"... I think that really helped.
Suffice to say; this was years and year ago. Recounting it seems like it happened to someone else, and I'm certain that my staff now would be astonished if they'd known I'd ever had a 'wobble'.
Keep us posted on how things go won't you, and look after yourself - it's not easy holding the fort together for everyone, so take care of yourself too xxxx