Just some unwarranted advice, the energy thing can be changed with proper diet and exercise, I'm 35 and it's amazing what a difference eating paleo and exercising 3+ times a week has made.
Did all of that as well. Stopped smoking (over half a decade ago, so that was around your age I guess), reduced drinking (~1 glas of wine per week), I always did excercises (just have to do it far more seriously now the older I get as I no longer build muscles that easy) and eating far more healthy by now (although somewhat more since I stopped smoking as that had replaced my breakfasts back then). Less general movement due to working from home since a few years (no more walking to a job... that makes some difference, but I still walking a lot as I live without a car).
It all helps - really does. Just doesn't stop aging :-)
I'm 33 (soon to be 34), and fitter than I ever was in my 20s, with more energy.
Difference? Eating differently (low carbs, high protein), and exercising 3 times a week.
I also stopped smoking a year ago.
Quality of sleep is also way up there now.