Marriage invalid - in laws say

Hello Sir, I had a arya samaj mandir marriage in 2012, it was a love marriage and my husband had hidden it from his parents, though they knew about our affair and knew that he had come to delhi from mumbai to marry me but they didn't interfere. We got married in Oct. of 2012 and as he didn't have any ID or age proofs he produced the affidavit as age proof. Now after a year and a half, his parents come to know about it and threatened me and my family that they will take us to court on account of forcing my husband to marry me in-spite non marriageable age, they say my husband was 19 when we got married and it is an invalid marriage. My in-laws have returned to their home town with my husband leaving me behind. I feel helpless. My husband demands annulment, as we were not physical, I am not sure the reason of no physical relation was because he was going to cheat me or what....I don't know what to do. I dont want my marriage to end, Can I do anything? I have photographs of our marriage, marriage certificate which they say is invalid because of him being underage at the time of marriage. I feel cheated. Please advise.