May I ask how old your wife is?
She's in the midst of menopause. Yes, I'm aware of all the chemical changes she's going through. My own counselor (a woman ....) has flat out told me that women going through menopause go through horrible hormonal changes and imbalances that affect them physically and mentally.
Menopause isn't the only thing however, you had to read the original thread (linked above) and the specific post I linked to, to understand what she's going through -- and refuses to deal with it. (I'd rather not repeat that all here....)