Husband doesn't believe in God anymore

I'm christian. Me and my husband have 5 kids together and we have always raised them religious. I found out that my husband stopped believing in God over a year ago and never told me. He only told his mom and his therapist. I saw the text messages between him and his mom about it. I asked him about it and he said he lost faith in religion as a whole because of something that happened almost 2 years ago that put him in therapy. I asked would he be open to seeing a Christian therapist through the church and he said no. He likes his therapist and she's helping a lot with his PTSD. I asked did he ever see himself coming back to Christianity and he said no. So I'm not sure what to do. I'm heart broken he never told me but his reasoning was he didn't want to ruin our marriage. Well where does our marriage go from here?