My boyfriend is refusing to marry me, what should I do?

3 years ago, he asked me out. I told him I want a serious relationship and do not want to casually date. He said he wanted the same. I told him we are from different castes and if his family will be okay with this as mine are pretty non conservative and do not mind different caste people. He said his family too was modern. Now 3 years later he suddenly told me that 'btw i wont be able to marry you because of different castes'. I was blindsided and reminded what he had said and he replied that he earlier thought he could marry me but now thinks he no longer can. From the past 7-8 days i have not been able to sleep, eat or stop crying. I do not know what to say or do. Edit - Okay reading all the comments I have decided to breakup with him. Now the only doubt I have is - should I inform his parents? I know they will get angry but does this guy not deserve the consequences of his actions? Or should I take the high ground and not do this and be the bigger person?