But you shouldn't be so hard on yourself, because you - anybody, me, you, most people you know, whatever - are raised on Disney movies and romcoms, so you implicitly, by default, view people a certain way. Let's call this view the "fragile angel" view, wherein humans are Basically Good but can become broken and insane by accident or birth.
Why single out Disney movies? Lots of them have people being betrayed by someone they thought trustworthy. Generally it's obvious to the audience who the villain is, but Disney has been playing around with their formula quite a bit recently - for example, have you seen Frozen?
This is the earlier promised post about Dealing with a Major Personal Crisis. Please continue reading there but comment here.
The reasons for posting it this way are explained at the end of the link. I hope this approach does what I want it to.