All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
First of all, we thank and praise Allaah Who guided you to Islam and we ask Him to make you firm and steadfast on His Religion until the Day you meet Him.
Dear sister, we advise you to seek beneficial knowledge, perform good deeds and befriend righteous and pious women, as these are the best things that help a Muslim remain steadfast on his/her religion.
Your husband should not have asked you about your past or tried to reveal what Allaah has concealed for you. However, you were wrong for informing him about what happened between you and that man, and also you were wrong for contradicting yourself.
Therefore, what we advise you to do now is to remind your husband that the past is over and that Islam wipes out previous sins, and that whoever embraces Islam and becomes a good Muslim, Allaah turns his/her sins that he/she committed in Jaahiliyyah [i.e. before Islam] into good deeds as Allaah Says (what means): {Except for those who repent, believe and do righteous work. For them Allaah will replace their evil deeds with good.} [Quran 25:70]
Hence, he should look to the future and forget the past, and be keen on doing anything that brings affection and leads to better marital relationship and not do what would cause dissension and the breaking up of the family.
You should clarify to your husband that you read in some Fataawa that it is not permissible for either spouses to inform the other about what he/she did in the past and that none of them has the right to ask the other about this in principle, and you may show him some Fataawa in this regard like Fataawa 84052 and 83259.
Finally, you should be wise in dealing with him and ask Allaah to enable him to regain his senses and reason.
Allaah Knows best.