Years Old

So I really think that I am getting OLD because I have basically had 2 jobs at a time for most of my working life and I was always able to do it but now I am starting to get really tired/exhausted from it and that means I'm old. I am pretty sure that in my head, to myself I am about 19 and I pick 19 because my lifestyle today basically is the same now as it was when I was that age (just with less friends now ha ha!) and I don't feel like a "grown up" I realized this, for the hundredth time, when I was talking to one of my coworkers about an upcoming event that I am in charge of and I said "I don't think I would feel as stressed about it all if there was an adult in charge" ha ha HONESTLY I wasn't even trying to make a joke!! I stopped myself and had to remember that I am almost freaking 27 years old! What do you do when you're 27? Is that the age when you become a real adult? If not, when is it? I need some input here because that number seems big and complicated and I don't know if I can handle big and complicated. I can handle turning 20 -- in my head, that's what comes after 19 right? maybe towards the end of next year I can submit mission papers... I think it would be cool to turn into a crazy person instead of an adult, like Jessica, a lady I met in Argentina who was so so so so crazy and it makes me laugh every time I remember about her.
I know none of the above paragraph makes much sense, and the different sentences don't really connect or correspond with each other. That is because of my early-onset Alzheimer's Disease kicking in. I am getting OLD!!!!!!!