Angela, No one is holding a gun to their heads to have affairs, but they do find excuses for them. So, please do not take on the blame for him having one. After all, he could have said no and found another activity to make him happy.
I would suggest that you continue as you have been, but no more talks about the relationship, etc. He knows that you are there waiting and hoping for a reconciliation and starting over.
I would find activities and projects to work on and continue on w/your life as if he's on a vacation to some remote island and drops a post card off to you every so often. He needs to sense that you are moving forward w/your life and that life doesn't stand still for anyone.
I think the best thing for you is to go dim. Text or call him only if it's absolutely an emergency. You have to make a decision about boundaries. In some cases having sex w/the spouse will keep them connected...but it also is considered a form of cake eating. He's got the best of both worlds right now and you have to decide whether this is what you want to continue doing. My advice is to get yourself checked out to ensure that you are healthy. They may say they are just friends, but you don't know what he's doing when he's not at home.
I would suggest that you think about seeking some legal counsel to know what your rights are and above all else, don't worry about what he thinks about you opening your own account. You did it to protect your assets and trust me, one day very soon, you'll be glad you did that.
Please make an appointment and have yourself checked out. I've met a few women who were in situations very similar to yours and they ended up w/the gift that keeps on giving. I do not want to see that happen to you or anyone else on this forum.
Just be yourself and continue to listen, validate and provide lots of space and time to your h.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.