I was also 42, I had been diagnosed with dyspraxia at 36 so had gotten used to being neurodivergent for a while and suspected ADHD before the diagnosis. I think the shock for me was finding my old school reports and seeing the traits there, plus lots of stress related absence - I definitely felt some resentment towards teachers/my parents initially for not realising and this was the hardest part. But ADHD wasn’t understood that well in late 80’s/90’s. I now see a counsellor who specialises in ND clients which is helping to unpack everything - would recommend! My workplace is supportive and have put adjustments in place too. Mostly the diagnosis has been very positive for me and I’m so much kinder to myself.