My wife did this too. Blamed me for all her unhappiness even though I spend 13.5 years trying to make her happy and to save her.
I also took all the blame that she laid at my feet. She worked for well over a year to go from being positive about me and us to blowing every small thing into some life ending affront by me against her.
It really wore on me as she started treating me worse but I loved her and I was trying to be the best person I could be for her but not myself, so my depression based on her unloving and unkind treatment really got to me.
Her mom used to bring her back to reality. Her mom was a miserable woman and it ended up costing her her life (stage 4 cancer once it was found at ~55 years old). Her grandmother was an even more miserable person but was also mean, cynical, and critical on top of miserable. These are the women she was raised with, well and a divorced father that didn't give a fuck about her, not to mention her siblings and friends treating her poorly.
She found an older woman that is dumb as a new best friend. That way her low self esteem about her intelligence won't be triggered (she's very smart, just lacks confidence). She's also her new "mom", but the issue is she's fucked up too. So now her issues were pushed onto my wife. All the abusive guys she dated were now compared to me. And even though I would discuss with my now ex-wife, she latched on to that like a lifeline. Because if I were bad, well she HAD TO LEAVE, lol. The truth is she never loved me, I found a fucking 5th breakup note yesterday that I'd forgotten about, I thought she only broke up with me 4x. She also got off her meds, because now she was free! So she stopped her bipolar/anxiety meds (which she'd been on long before meeting me) and switched to seemingly becoming an alcoholic + pothead. But she's free now...
How I thought I could save her is beyond me. She's still very childlike because like a fool, I did take care of her (one of my big issues is care-taking to "win" love).
In the end, it just fucking hurts. It's hard to accept that the woman you loved just used you. She loved what I did for her, but never me, she just knew she couldn't do better. The funny thing is she's right, she'll never get to 50% the man I am. I wouldn't have said this ~9 months ago when she left. But after dating women and seeing what their options are, it's not good out there even if you're beautiful, successful, intelligent, caring, and well adjusted. Imagine how bad it is for an obese woman that's fucked up with substance abuse issues and low self esteem. But hey, she can get dudes from Tinder to come fuck her, they just won't take her to dinner because they don't want to be seen with her.
I'm angry as fuck. I'm angry at myself for accepting her as a partner and for allowing myself to love her in spite of all her flaws. I'm angry at her for lying to me for well over a decade and not being a good person by simply letting me go instead of making me into a monster that I'm not.
I'm a fucking awesome person. Flawless, no, but I work extraordinarily hard on myself and my relationships. I can be defensive but I will always listen and work to improve myself to meet my partner's needs (assuming they're reasonable of course).
I'll find love again and maybe it will actually be a two way street, but if I don't, that's fine too. I will never settle for someone again. I really liked my last gf, we're still friends, but she just didn't make the cut in the relationship department. Too many fixes left and I don't have time to wait nor do I have the absurd belief that I can help fix anyone but myself anymore.
Sorry for the long rant, your post just soundly hit home.
Hugs, you deserved much better.