I'm gonna respond from my gut, based on what I read in this post. I haven't read any other post by you, so I have no idea of other details that may fill in your story.
Toxic. Terrible, debilitating toxicity. And I'm not speaking about your brother.
If you are truly seeking happiness for yourself, and not retribution for having survived a malignant parent, then you're going to need to work very hard on your own recovery. It is an oftentimes exhausting and ugly process, and for that many people avoid it, but as far I can see, that's the only way you'll be able to break out of the immense protective structure that you needed to build in order to survive – you need to leave that place, because it has turned into a spiritual deathtrap.
There are many on this site who have done similar work, so it's not like you're alone in this. It is possible to begin to love yourself, and your present doesn't have to be a constant replaying of your past. I offer you my very best wishes.