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.
Indeed, you did well by regretting what you did but your regret should be translated into a sincere repentance as well; for more benefit on the conditions of repentance, please refer to Fatwa 86527.
You should be careful not to do this sin again in the future, and you should avoid being in seclusion with non-Mahram men or other matters that lead to Zina (fornication or adultery). Indeed, your committing Zina several times is evidence of your weak faith and also evidence of being negligent and lenient in dealing with non-Mahram men. For more benefit on the means that lead to Zina, please refer to Fataawa 81356 and 84419.
Dear sister, if your marriage took place while you were committing Zina with the other man, then you did not clarify to us whether the man who married you did so after making sure that you are not pregnant from Zina, because it is not permissible to marry a woman who committed Zina unless one makes sure that she is not pregnant from it [by having one monthly period]. However, if the marriage took place before making sure that she is not pregnant from Zina with the presence of her guardian and two witnesses, then the marriage is correct according to the scholars who are of the view that such marriage is valid; for more benefit, please refer to Fatwa 135767.
If there is any child from such marriage and the wife gave birth to him more than six months after marriage, then the child should be traced back to the husband but if this took place less than six month after marriage, then the child is not traced back to him, rather he should be traced back to the mother.
As regards the marriage of that other man to you, then if you are still in your waiting period, it is not permissible for him to marry you, and the marriage is void until the expiry of your waiting period. For more benefit on the marriage of a woman during her waiting period, please refer to Fataawa 90732 and 92637.
Allaah Knows best.