I was diagnosed about a year ago when I was 30.
Overall I have had a slight improvement after getting a diagnosis. My post history will give you more details if you're interested.
I tried medication. I find it helps a little. Better than not having it. Temper your expectations. Some people get big improvements, others get very little. It's just one part of the puzzle.
Other therapies can help too. ADHD counsellors and coaches. CBT. Medication might help you to access these.
Really, there is basically no downside to getting a diagnosis. You could decide to not take medication and you wouldn't be any worse off than before.
If you are noticing a relatively sudden change it might be worth getting a physical to rule out any other deficiencies/health problems that could be contributing to your issues too.
Good luck with your journey. Remember, changes take time. You wouldn't go for a jog one day and then say you're done with fitness. Mental health and fitness take constant care, attention and effort.