Should I tell his mother?

We had a registered marriage and his mother does not know about it, his sister knows. we are living as separate individuals. He has unmarried sister and he indirectly asked his mother that he wanted to marry me but his mother refused owing to age (I am elder to him by few years), waiting for his sister to get married. I waited for things to settle down, but now he is saying to just leave him forever and not pressurize him to let mother know about our marriage and even his sister is asking me to leave him forever. I am feeling frustrated/cheated and wanted to solve this amicably but now he is not willing to listen and does not answer any calls made by my father to him. He is telling common friends I am like his sister. I want to know if I can save this marriage or is divorce the only option? whether his mother will accept me as her bahu If i tell her about our marriage is it worth spending my whole life with this kind of person who is hesitant to disclose marriage?