I can relate to you quite a bit, aside. There was a point in my marriage where I figured my game plan was going to be to remain in my marriage, to pretend to be Muslim forever, and to kind of buy myself some space and freedom by arguing about Islam.
Things went fairly well, to be honest, and the only things that really bothered me were situational anxieties about possibly moving to a sharia state or raising kids who were trained to accept science as the glorified opinion of those atheists/Zionists out to make Islam look bad.
When I first met my husband, he wasn't incredibly strict, I've known far worse, but he had some pretty high expectations for what a good Muslim and his wife should be, and I slowly began to drop the ball. When he began to complain, I really had to up my arguments, and it wasn't that difficult, but it also wasn't loads of fun. But after enough time went on, it didn't matter how well he and I got along ordinarily (we had no other complaints with each other at all), I started to really resent him in some ways, especially when it was difficult to reason with him during the Islamic arguments, especially when I heard him repeating some of the most mind-numbing and illogical nonsense to ever be uttered by theists, and
especially when I was made to feel like the one who was both unintelligent and in error.
I know what you mean: like you, I had almost no interest in any "haram" things either. I sit at home and I knit.
I didn't feel like I was being deprived of something, I didn't feel like I was missing out on anything. But the stress kept building, anyway.
My circumstance eventually found my husband more or less gathering that I have lost my faith without me even saying it, and we haven't been any worse for wear yet, but when I look back on what I was doing just months ago, assuring myself I'd be content with being perpetually on trial, I don't know how I was ever happy. I feel so much better now, and if my husband tried pushing me again and putting me in that position, I would no longer stay. It sounds like leaving your wife isn't even an option to you, but it is really sad to see you doing what I did: committing to a lifetime of deception and sacrifice to stay with someone who would leave you if they knew you, or whose relationship with you might become strained.
If you're anything like me, even if you could see yourself keeping this balancing act up indefinitely now, there may come a time when something has to give, whether it will be that you are able to soften your wife's religious views up to be more lenient (at the moment, my husband's religious views are nearly identical to my old ones), or that you will have to come clean and see what happens (which I would not do without consulting a lawyer, considering your children). To just take it all upon yourself to keep the relationship together is always going to be a very stressful thing. I doubt that anything can change that unless you're both willing to meet each other halfway.
If you really do decide to just bite the bullet and continue on, on the plus side, the people here are fantastic, and usually at least one or two people will know exactly what you're going through. So at least you'll have CEMB to vent and recalibrate your system.
Good luck, no matter what you decide!
Topic: Losing my mental health