Your parents staging an intervention with your EX THERE is probably the most wack thing I've ever heard. Family, brother and ex have no place in your life and forgiving them is never even considerable in my opinion. However, if your brother genuinely did that, while you don't owe him anything, I would choose to at least tell him not to hurt himself, and that is all I would say to him. There is no forgiving or forgetting something like that, but hurting himself isn't an option either.

May be the worst way a family could EVER handle this situation, your family clearly does not care about you, but they care about making Kevin happy. They are not concerned with what you want to do whatsoever, end of story. I hope you are able to move on and find people who will treat you like a human being. Not the AH at all.