To be quite honest, I am not sure why you are still in this relationship. You do not describe any positive aspects, only negative. It’s as if she is on a mission to make you feel crazy. It makes me wonder if she might have a personality disorder.
I realize that you may have left the positive aspects out of your question, focusing in on the problems, but even if she has some wonderful qualities is it enough to make the relationship worthwhile for you? I don’t know her full history but there are many people who have been teased by their brothers and who have had some adversity in their childhoods who still grow up knowing how to show respect to others.
If you choose to continue in the relationship I think it would be necessary to get some couples therapy and she might also benefit from individual therapy. However, given what you have described, I feel that you are justified in just breaking it off and finding someone who treats you with kindness and respect.
All the best,
Dr. Holly Counts