I don't know where mine came from, since my childhood was pretty good. We knew we were loved, even tho we were disciplined when we did wrong. We were never abused in any way.
I remember getting my diagnosis and being put on sertraline. It took a few weeks before I felt any better but it was quite a difference. My bf noticed the change and told me it made me into a better person. I said, well then, why don't you take it too?
(we didn't get along well at that point) It was also pre-menopause depression and the zoloft helped that a lot.
There were side effects to it, for the first few weeks, but now, I can't remember what they were.
I'm sorry you went thru all that crap.
Going NC with your sisters might be the best thing, if they're such a negative influence.
Sending you more hugs.