Thanks for your reply!

My boyfriend seems to be torn in the situation, he doesn't want to hurt me, nor his brother. Which I understand, to the point. If he is being serious about our relationship - and he says he is - I was hoping he will do something about it, but, as far as I know, the conversation only made things worse (I wasn't invited to see the little baby and the brother said he won't speak in English 'cos that's not his language).
My bf's parents are coming over from Iran soon too, and I am really afraid what is going to happen. I mean, should I just act like nothing's ever happened and that we are all a happy family here? I feel like he (the brother) is starting to win, since I am even writing the post in here! Think I should do as you've mentioned - try to gain the power back. It's tough though!