Thanks for sharing such a brave and raw post, and very relieved that you found happiness in the end.
Regarding the bit about reporting people, I’ve done it before (not Facebook, elsewhere) because I was in another country, didn’t know the person and did not want to play armchair psychologist and make the situation worse.
If you see a stranger’s house on fire, you don’t try to tackle the blaze yourself.
Given what you said about not forming a robust support network around yourself, it’s pretty likely that the person who called the cops was a stranger being a good citizen, not a close friend who let you down.