Go to your priest. And acknowledge to your husband that you know. If he has a conscience it will scare him. If he has a conscience, he will want out, and you tell him to see the priest, NOW. If he goes on, in mortal sin, the next thing will be the devil encouraging him to commit ѕυιcιdє.
Ask God for His Son's Precious Blood! Plead with all the cohort of the heavens and those in purgatory to help in prayers and intercession.
How old is your husband? Are there children? His age? If he is age 40 or more, his hormones may be like those of women at that age. they need b complex shots. Some may feel the "empty nest" syndrome. But act quick! Let your husband know what you know and see how he reacts. Prayers-Songbird.