I'm sorry that you're here and hurting. These boards are like a double-edged sword. Never in your life would you have wanted to be posting on here, and yet there's so much insight to be absorbed through all the posts, not just for marriage advice but self-help too.
I made all the normal mistakes when I found out about my wife's A and didn't start putting some of the tips I've learned here into action until 5 months later. I wish I had come here sooner, things might be different now.
Your story reminds me of mine in a lot of ways. If you substitute two children for your H's demanding career and the business you've been trying to run, it sounds like the same progression that led my W and me to where we are now. In the simplest terms, we didn't put any effort into keeping our connection to each other strong. Schedules conflicted, priorities got shifted.
My mistake was that I took my marriage for granted and just assumed that we would always have a core connection to each other and would get back to our marriage when things "died down a bit". But over the past 9 months I've learned 2 things:
1. You can never maintain a core connection to your partner if you don't nurture it on a regular basis.
2. Life never "dies down".
So we grew apart without me even realizing it. I turned inward and spent all my free time on my own hobbies. She turned outward and found an emotional connection with another man. Only recently have I started to understand that both of these were a betrayal to the marriage.
Everyone's advice on your post so far is spot on. Focus on yourself. Don't let your fears and insecurities about your marriage and your H's behavior paralyze or stagnate you. Get on with getting on. Make some time to distract yourself from the situation: friends, family, hobbies, exercise, etc. But also make some time to figure out what YOU did to get to this point and start working on fixing it. Therapy, meditation, religion, self-help, and these boards can definitely help with that. But try to find a balance - you can't JUST disconnect and distract yourself all the time, nor can you spend all your time thinking about fixing your issues.
Whenever you're in contact with your H always keep in mind that trying to address the problems in your marriage when you are both hurting and emotionally disconnected will only make matters worse. This is one of the reasons why so many people will say that marriage counseling doesn't work. Steven Covey says, "You can't talk your way out of a situation you behaved yourself into."
Instead, try your best to keep things light. Inevitably you will have to talk to your H about logistical things related to the family and the business, but try to find opportunities to share a few moments that foster some kind of connection between the two of you. In my case, my W ALWAYS laughs at my jokes so I have an easy in. Once or twice a week I try to call her in the middle of the day, if she answers I go right into the joke, wait for her to (hopefully) laugh and then say, "Ok, goodbye" and probably leaving her totally perplexed about why I called.
Please understand that this approach will not work for everyone, but it's resonating with me more than any other approach I've tried so far, so I'm going to keep at it. In a nutshell, I'm taking action right NOW to be a better husband. I don't need my W's help with this I can do it alone. My hope is that my changes inspire something in her which lead to us trying to piece the M back together. But if they don't, I'm still better off than I was and I'm getting real-world practice for my next relationship.
I hope this helps. And keep posting, even if it's just to journal your thoughts and not ask for advice. It always helps and it keeps your thread on the first page for more people to notice.
M46 W48 M11 T14 S11 D8 BD: 2016/05/27 In-home separation: 2016/11/23 Nesting: 2017/06/11 W moves out: 2018/01/07 W goes public with OM: 2018/07/12 I ask for a divorce: 2018/12/14