If a woman does find out that her husband is gay, she shouldn’t blame herself, lash out at her husband, or try to change him with tools like conversion therapy, which has been proven to be harmful and ineffective (Cornell University has compiled a vast collection of research debunking these approaches).
Instead, the woman should continue seeking support from a therapist. Her therapist can help her see this is a situation that’s outside of her control and provide guidance so she responds in a way that’s healthy for everyone.
If you are contemplating divorce consider reading more about Discernment Counseling.
There are also LGBT-affirmative counselors available to talk through concerns about your sexual identity.