All of this - the biggest advantage of my late ADHD diagnosis has been the understanding of why I feel, react and behave the way I do and means that I can access ADHD specific tools to help.
But it does change the way you behave and interact with others - including those closest to you as you no longer need to constantly mask and filter your feelings through the lens of what is normal.
That doesn't mean to say I now expect to have everything my way - but it does mean that my DH knows that if we go somewhere busy, I will need time to decompress afterwards.
I think it is also unfair if OPs DH is not willing to understand what having ADHD actually means or how it presents and affects the OP. My DH has listened to me talk about it and explain the different elements.
While he has always been supportive (recognising when I need time alone or when I am not myself), now we know that the time alone is because I am overstimulated. He can spot when I am getting hyperactive or hyper-focussed before I do and checks in that I have taken my meds.
He can see when I am suffering from decision paralysis and proactively steps in rather than waiting for me to ask for help as he would previously (which would happen sometime never).
I can also talk to him more when I feel the rejection sensitivity kicking in - whereas before, I would never voice those concerns because I thought it made me sound paranoid.
Being able to take the mask off at home is a massive help as the constant masking, internalised struggles and inability to plan and be organised like other people pre-diagnosis led to burnout and nearly to a complete breakdown.
People who say that loved ones don't want to hear it because you are who you have always been don't get that ADHD can cause you to mask your true self even from those who are closest to you! A late diagnosis is a big deal because it fundamentally changes your perception of yourself and forces you to reframe your entire history.
@Thevegetarianchef - I would definitely recommend counselling and / or ADHD coaching, it's really helpful! I also recommend reading Now It All Makes Sense by Alex Partridge and The ADHD Women's Wellbeing Toolkit by Kate Moryoussef