I believe you when you say you can't place your finger on why you're suffering from mental health issues. It doesn't necessarily have to be abuse, or a deep-seated resentment of something.
Living as a woman in a patriarchal society, where women are disenfranchised in all areas of life (political, social, economic- women are poor) and where men make powerful decisions that affect womens' lives is incredibly stressful for women; and this is not addressed properly.
FOr example in the case of PND, it's passed of as being hormonal, or something that naturally happens to women. Nobody questions whether or not the woman suffered birth trauma in hospital, whether she got the support she needed post-partum, whether she has enough help around the house, enough money, a respite etc etc. She's just pumped with drugs. And even if somebody did bother to find out if there was an environmental reason, there aren't the resources to help her in the first place, so again, she'll be offered drugs.
Modern living, in itself, is incredibly stressful. SOme cope, some don't, but I don't think the default line of thinking should be that the person is inherently wired wrong IYSWIM