Dear Friend,
You are a human being. Yes, you are a wife. More than that you are a mother. Mistakes in life are common. It is not fair to repeat the same mistake. That is what you are thinking of. As you as simply the nature's call, was not fair. Ask to yourself,
1. Are you really a good wife?
2. Are you really a good mother?
As I said mistakes are human nature. But repeating the same mistake is cheating. So, completely avoid the relation with that "friend"( He is not a good friend, he is also cheating himself and his family too.He is too clever and cheating you.)
And now,
Think about your family, your husband, your children. There will not be another wife to your husband, but you. There will not be another mother to your children , but you. So you are a VERY IMPORTANT PERSON to your family. With out you your hsband and children can not live. You are the backbone of your family. So always think about you and your family. Other so-called friends are pretending figures.
Try to practice YOGA for realaxation. It will do a lot to your life. Good luck.
Have a nice time!