A structural fix is something that you pay for up-front and which then continues to serve your life with zero or little in the way of ongoing maintenance costs.
Some examples, feel free to add more:
-If your computer is swapping (you hear the hard drive churning) during normal usage, get more RAM! Getting an SSD hard drive is also a good idea. Swapping out to disk is like sending a sailboat across the Atlantic to fetch your stuff, whereas RAM is like getting it from your pocket.
-Buy everything you can find that can optimize your sleep. Some ideas: blackout curtains for your sleeping quarters, Zeo device, supplements known to aid sleep (melatonin, zinc, stuff like that), Philips Golite, earthing mat, etc.
-Get a good digital scale with bodyfat measurements and all that jazz. Make a habit to enter it into a suitable tracking tool. Hacker's Diet is good for weight. Even better if it auto-tracks the data for you.