What do I do?...kinda long

My husband is a "smart" guy, in a way that he is a graduate from one of the best schools and makes "more than average"money for someone his age. But he is strong headed.If he is in a debate or any discussion then he defends his side so much that others (including me) think that he is arrogant and wants to show of his intellectual superiority. Some of my relatives have earlier got hurt by his behavior and have told me about it.The problem is,he thinks whatever he does is the only right thing.There is no point of me explaining to him (I have tried a million times). Sometimes in a discussion if I give an opinion he shuts me down saying :it's pointless".I feel embarrassed, if he does that in front of other relatives.I was in almost as good job as him but I left my job to relocate for his.So, it's difficult for me to accept that someone questions my intelligence too. Apart from that, he has strict rules for me that I don't give opinions in his family matters and he maintains a secret text group of his siblings. But he sure does put his opinion to my family matters and shuts others up. I am too frustrated with this.I don't want to be treated as a fool and nor so I want friends and family hating him. What do I do?