I can't see into the future sadly. But I'd hate for you to "give up" simply because you can't see a way out. Of course, I'm the pot calling the kettle black there. If you look over at my sitch, we've been together for a long time (8 years) but I'm only 27 and he basically left me for OW.
As far as how to show him changes from across the country: it means you have to use every interaction to show him something new. For now, that means going dim until he comes to the table more. IMO, if he asks something about business stuff (taxes, etc), I wouldn't just ignore him. But I would treat it like a business interaction. You've made it clear to him that you want to work on this. THe best way to do that right now is to work on yourself. Look at the things he's saying are wrong. (we can help with this) What is your role in that dysfunction? Are you in counseling? Is he? I don't bring up the idea of OW to try and throw you. I only bring it up because what you have to realize (and what I"m still trying to realize) is that as long as there are 3 people in the marriage, it'll never work. So you remove yourself as an option until things blow up with the affair. Is he acting differently than he has been? Does he seem like he's just stressed or does it seem like overnight he became a pod person? (those are the things I saw when my H started his affair. Suddenly I became the sole reason he was unhappy. He stopped complaining about his job and just complained about me). So for hypothetical sake: if there is OW. The choice then is yours. Can you move forward if he's had an affair? There are a lot of people (and honestly, I wish I was one of them) who say Nope, you cheated. I'm done. If thats who you are, I think you need to do some digging and see if you can find any evidence. If you aren't, then it doesn't actually change your tactic that much. You still go dark and wait for him to approach you.
There will be a lot of people who come in and give advice. I'm by no means a vet. I'm neck deep in my own situation and I feel pretty hopeless most days. But for whatever reason, I find its easier for me to provide perspective to other people. That's why we suggest you read other sitches and post there. Because you do have something valuable to say, even if it's just words of encouragement. And it's a proven fact that helping people makes us feel better about ourselves.
All of that said: again, I don't have a crystal ball. But I've seen sitches with much more to overcome than yours. There's still hope if you want there to be. Remember: its always darkest before the dawn. Nows the time to work on your stuff. Work on what you can fix. That's all you really can do. Try and show H through actions, not words, that you're willing to do what it takes to make things work. Real change starts from within us, not by trying change someone else.
Keep posting!
M:26 H:32 T:8yrs ILYBNILWY/ "I'm not happy": 2/6/16 D-Day-discovered PA/EA: 2/10/16 Separated: 2/14/16 He's living with OW I moved to different state: 06/16 Currently: Trying to move forward