I was in the same situation as were other of my family members, younger and older.
What changed my life (and everyone else's) was to get into vitamin therapy with supplements:
B12,
D3,
Omega 3 oil (lemon flavored) and
Vitamin C.
If you can get lab work to test all your vitamin/mineral levels, I strongly suggest you do. You'll have a baseline to measure your gains. I got lab work every 3 months for 2 years to track my scores
There is current research on
D3 and
B12 and
Omega 3 levels being too low in most people. Your body's ability to absorb nutrients changes for the worse over time, no matter how much good stuff you eat. Extra low B12 can lead to dimentia. All 3 can affect memory and energy levels.
Most of my levels were middle to low. My calcium was high so I don't take multivitamins or calcium supplements. Also, daily vitamins won't necessarily boost your low vitamin levels.
Since only my calcium levels were at the top of the range, and since no doctor was able to tell me what is OPTIMAL for ME for the other vitamins/minerals, I made it my goal to raise all of my middle to low vitamin levels to the top of the range.
As a result of vitamin therapy, my memory(short/long term recall),energy levels and immune system have been and continue to be greatly enhanced.
I have been ill for only 2 days in the last 2 years. And it wasn't as intense as I usually get. Previously I always had to get on some kind of medication.
I also cut my
salt intake to about half the recommended daily value(2300mg daily). Reducing salt decreases the effort your body(heart, kidneys) exerts to remove waste and overflow. Thus, reducing inflammation that can affect your blood vessels, brain, etc.
Also be sure you're getting good sleep..6-7 hours. Sleep deprivation/poor sleep will decrease energy and memory retention in addition to reducing your ability to focus.
Vitamins are cheap so there's not much of a downside to testing them out for 6months to a year to find out if they can help.
Note: the links above are to the products I actually use. Obviously, you can buy anything that may fit your goals. YMMV, IMO, IME, etc. Check with your health care provider before making any changes.
As far as stress goes, PTSD is the result of ongoing too much stress. I suggest spending more time in the sun and taking a few weekends off per year to de-stress. IME, it may take longer, depending on your level of stress. Working out as often as possible get your muscles working, blood moving through your system and produces lots of good stuff (hormones, chemicals, etc.) for your brain and body.
Good luck.