I was diagnosed with depression at 10 and wasn't diagnosed with BP until 29 despite the symptoms being present, and am now age 40. Some if it was my doing as I only ever talked about the depressive symptoms and only went in when depressed. I never knew that hypomanic symptoms were an issue, to me they were great compared to the depression; I would be more functioning than with the depression and did not want this taken away. This delayed a correct diagnosis for me for years until it could not be hidden. It saved me in the end when a doc figured it out.
Age feels relative to me as some days I feel so much older than I am and others not so much so, feeling so small, clueless, and insignificant. So much happens in life, all the ups and down, more downs though. However, have also learned how short life can be no matter how old one is. So for that reason I just think of it as I am blessed with a few more years of experience that I have learned from, but have MUCH more to learn every day to be as wise as those who are years ahead. Can only hope. I also hope from one day to the next I'll have that opportunity to discover what's next and get a chance for those new experiences.
I hope you find what brings you comfort and balance no matter what age, is a beautiful thing.