I second that, therapy is the key.
I've been through religious abuse myself. And I know well how it feels, to be forced to stay with those who are gaslighting you, for the lack of other options. Also, black sheep, hell yeah...
It's hard to tell in advance, what kind of therapy (and therapist!) will work best for you. Everyone is different. You may need to look around and try before you find the right one. Just don't get discouraged, I've found the right one for me in a backwater town in the middle of nowhere, of all places.
Her approach is a bit special. So-called process-oriented therapy, focused on feelings, emotions, associations and the "flow" of what is going on at the moment, rather than purely logical explanations (as in the case of CBT, for example) Of course, there could be very down-to-earth parts too, but they weren't the sole focus. Can even get somewhat "shamanic", with guided meditation/trance used with those who are willing to try such methods. For me it worked wonders.
Books helped a lot too. It's great if you can get some that are talking about your issues. For me the choice was rather limited, but even the most general books about psychology were helpful, as they made me more aware of what is going on in my mind.
Best of luck, and the most important thing, don't give up! I've learned through experience that the solutions are out there, and even if none is in sight at the given moment, it's the matter of searching and finding them.