Eh I think you give us "strong" 20 somethings a little too much credit.
You forget a lot of us drink heavily, have a horrible diet, and barely sleep. I have actually have felt like this since last year some time, but I thought it was just natural b/c I drank too much. And my tinnitus annoyed me so much I had to find a reason for it.
It was definitely a combination of metals, Antibiotics , really bad habits, and stress for me (I'm 20). Even at my age I can only take so much. Next year though I'm going tobe super healthy