Was this wrong of me to do to my gf........ if it wasn't why do i feel guilty ...... ?

my ex gf has had a very trouble life.. she was molested twice as a child, d in her 20s,, and got divorced at 34... i was 28 when i met her. we dated for 2 years, and had a very nasty break up. She basically wound up leaving me for someone else... someone who was a member of evangelical church ( I am agnostic, and her family didn't like that about me) Anyway .. at first it was just supposed to be about the , and that was great we were both okay with that... especially her since she had been in a less marriage for 6 years. Then we got to know each other and we realized we had a lot in common and like to spend time with each other we turned a fwb relationship to a bf/gf realtionship. I fell for her .. and even started to mention marrying her... but she awlays had a problem with age differences, especially because her ex was older than her...so she would alawys just say we were just a fling.... anyway...she wound up leaving me...and went back to her religion.... but now i feel horrible because i jsut put her hyperuality and her cold behaivor in context.... and realize that she has serious mental issues that date back to her molestation.... and .. and she always had low self esteem....and thats probably why she ended up cheating... I dont know why i feel guilty but i do............ am i right to feel guilty for not having had figured it out in time and having her seen a professional ..... i didint notice it until i realized that she was really devout christain ... to the extreme.. but she wasnt that way when we were together... he family was... but she wasnt.... why do i feel guilty ...