OP, I completely understand where you are coming from and will share a little about my recent experience.
I have always felt like I was living life on hard mode, I have always worked hard but all my accomplishments I fought tooth and nail for and was always quite stressed, with racing thoughts and a lot of chaos in my brain.
I thought everyone was like this so didn’t really think much of it.
It was in my late 30s that I felt life starting to unravel, becoming a parent, progressing at work, hitting a certain time of life, it felt like I couldn’t cope anymore and I started dreading work, missing deadlines in and out of work, and generally not taking much joy from life. I had no idea what this feeling was but knew it wasn’t going away and I was beginning to feel incredibly burned out and cyclical about life.
I referred myself privately and went down an ASD, then ADHD route. When the ADHD diagnosis was confirmed I felt relieved, seen and heard. My whole life looked different in retrospect and I did mourn for my younger self who had no idea she was struggling.
Im reasonably early post-diagnosis so am going to progress therapeutic/ coaching routes, I have also started medication and it’s made such a huge different in my self confidence, ability to get things done and general feelings about life. It’s been massive for me, it may not work for everyone, but if you are curious about it, I would recommend giving it a go if you get the opportunity.
Good luck with the process, it’s extremely admin heavy in my experience (doesn’t really play to our strengths!), but it’s worth it to get the answers you are seeking either way.