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.
We have already referred you to some Fataawa which clarify the validity of marriage of a woman who committed Zina (fornication or adultery) if she married before she had repented according to the view of some scholars, and we referred you as well to some Fataawa which clarify that some scholars are of the view that the marriage of a woman who committed Zina is valid even before making sure whether or not she is pregnant. For more benefit, please refer to Fataawa 83176, 89292 and 135767.
Therefore, your marriage is valid according to the view of those scholars, and their opinion applies in case one has committed the complete Zina, let alone the fact that this (complete Zina) did not take place between you and your husband as you mentioned. So, why all these whispers and doubts?
Dear Sister, the solution is in your hands. So, avoid these whispers of the devil and do not think about them, rather seek refuge in Allaah from the devil when you have such whispers. Moreover, you should not ask again about this issue or move from one Mufti to another in asking about its ruling.
Finally, you should continue your life with your husband as if nothing had happened. You are his wife and you are not obliged to leave him; rather, it is not permissible for you to leave him unless he divorces you or that you seek Khul’ from him.
Allaah Knows best.