She has had a traumatic life, as my W has. You aren't responsible for what happened in her life before she met you. And I can guarantee you, some of this stuff happening now is a result of what she's been through before she even met you.
Hurt people hurt people. You can't fix her nor can you take ALL the blame for things falling apart. She played a role as well but decided to hit the eject button. You didn't.
Think about it... she left her Lawyer husband who has been a father figure to her children for a trailer park simpleton.
^^^ Do you think that is normal? She has issues, clearly.
Stop blaming yourself, Tim. She could have been married to Dr Phil and still would have found a way to implode.