Good first step.
I'm a BS and I would agree that my marriage was broken before her A started.
BUT . . . I didn't know it at the time. And, she never came to me and said "Our marriage is far less than it should be, let's work on it"
In our reconciliation and healing, we worked on healing ourselves and each other from the A first. And then work on the marriage came along later.
Folks are already saying this on this thread, but you're going to need to place healing, yours his and the marraiges, from the A at the top of the list of things to work on. If you guys can get through that, you'll be in a place where you can work on the marriage.
good luck and glad you're here