Rejection from boyfriends mum

Need some help please, I've been with my boyfriend for one year and we started to talk about marriage. I'm 18 and he's 26. We both agreed to it and he spoke to his mum about me and asked for my hand in marriage. She rejected me. I feel so heartbroken and upset I couldn't help but break down and cry because of how much I love and want to be with him. It's like she's thrown everything I've done for him and with him back in my face. We would essentially have to end a strong relationship which we both want over her no and I don't want to. I don't know what to do or say to him. Help please ?