38 years of lying

How do I even begin? Adultry from my husband in the first 5 years. (maybe more than once) on & off again problems w/alcoholism and now I've found out he's been using pot for who knows how long. How do I ever learn to trust him again? I'm sure he'll come home from work tonight remorseful. And I say " so what". I'm so discouraged...........we profess to be Christians all these years ( he served in the ministry for 10 yrs). I feel trapped. It would devastate my grown children & grandchildren if we divorced. I feel strongly that is not the right way. But I feel trapped. There is so much more........he's let me down in every way. I'm the primary bread earner, and I feel I don't even have time to work on this.