So sorry. It sounds hard. I dunno how old you & wife are, but maybe she is coming into a premenopausal time? My doc floored me at 40 saying I was going there...seemed wrong, but she said women can start having wacky hormonal issues pretty early. (huge bummer) If this is a possibility, there is help for that too.
My Huz is a button pusher & blamed any reaction I had to hormones; it was the handy catch-all for a while, but we still had to deal with some other issues. (His ADD is still unresolved & a big problem)
You can interview therapists ~ maybe both of you can make an effort to find one that works w/ your schedules, etc.?
And, maybe ask her if she needs help to stop the smoking? She already knows it is a bad idea.
All I know is teamwork/honesty are required in marriage. You are on the same team, right?
I applaud you for your care & concern for your partner. I wish you both the best as you work this through .
That's all I've got ~