After her husband died she found out that he was a Raafidi, and his behaviour was bad

O Shaykh, after my husband died, I found out about his betrayal. The evidence was films and pictures that he had. I found out that he was a Shi’i when I am a Sunni, and that he used to engage in witchcraft, homosexuality and zina, and he consumed people’s wealth unlawfully, but he was careful never to show anything. I also felt that he was a person who was completely different from us. By Allaah, when I looked at him whilst he was sleeping I felt that he was a criminal, and I used to say, Why do I feel this way? I was afraid of something unknown, and I was always anxious. I would miss him when he was away, but when he came and I looked at him, I would get these feelings. 
I know that I should conceal him and I have not mentioned this to anyone, not even his children. But I am tired and these things are on my mind night and day. I cannot forget him, even in my dreams, and when I am awake. What should I do? I have begun to hate everything, even my children, and food and drink, and he is always on my mind. What should I do?.

Praise be to Allaah.

What happened, happened, and now it is over according to what you say. Now you have no option but to learn a lesson for the future, to choose suitable husbands for your daughters and suitable wives for your sons. You have ahead of you the rest of the days that Allaah has decreed for you, so do not be preoccupied with grief, regret and sorrow, because that will not do you any good. Take care of yourself and turn away from that which will harm you and make you waste your life with no benefit. 

It is essential that you conceal this from your children, because no interest will be served by their knowing about it. 

Strive to teach your children the ‘aqeedah (beliefs) of Ahl al-Sunnah wa’l-Jamaa’ah, and give them a sound upbringing. 

Seek reward for your calamity with your Creator, and strive to do righteous deeds that will benefit you and your children. Do not pay any attention to the past, because it is behind you. Nothing can help except forgetting about him and doing that which will help and benefit you in spiritual and worldly terms. 

We ask Allaah to compensate you with good and to relieve you of worry and grief. 

And Allaah knows best.