There is no help out there, unless you mean medication, and it would be highly unusual for a previously undiagnosed adult to be given ADD medication. Reading up for self management tips is a good idea, and an official diagnosis might help your DH to understand how his brain works differently... but it does not give him an 'excuse' for his procrastination!!
I am married to an adult ADHD-er and my DD1 is an adult ADHD-er, diagnosed as a child, medicated and still medicated as an adult (comes under the mental health services). Both need exercising constantly like large puppies, and it really helps them both .. helps calm the whirring non stop brains. DH is a cyclist and DD1 a gym nut
Without their exercise both find it hard to settle, can't focus etc.
However they have never been able to say 'oh this is how I am I can't help it' It's been a case of.. 'yes this is how you are, now find strategies to manage better' .. organisation? I do DH's, DD1 lives by her tablet diary. They can both show (and this is common for ADD/HD) perfect focus... if it interests them enough, they just don't apply any to the mundane stuff.
DD1 became obsessed with bodies as a small child... she's now 22 and in her final year of medicine, despite being a very inattentive and hyperactive child and teen (even at A level her chemistry teacher once shut her in a cupboard for 5 mins to give himself a break!!!) She is as diagnosed as they come, and yes needs meds too, but she knows she HAS to figure ways to manage.. it's all about wanting to.
There is little actual support for adults, and I think it would be difficult to get accomodations under the DDA at work to be honest.