All caught up on your sitch. Wow, I can't even begin to imagine the emotional pain you are experiencing after finding out about the other 2 A's. That is the ultimate kick in the nuts. Only you can decide what you can live with. Is 3 A's a deal breaker for you? I will say, based on what you've written, is that your W does appear to be remorseful for what she has done. With that, there is a chance for your M. My advice would be to take one day at a time. I wake up every single day and have to tell myself that I am going to stay in and work on my M today. Even when I feel it would be easier to just walk away. Now that your W is back, the truly hard work begins. This is not easy and you are going to continue to experience a wide range of unpleasant emotions. When someone has 1 A, they have issues. When they've had 3 A's, they have LOTS of issues. Your W needs IC on top of MC. I would strongly encourage you to help her find a good IC.
In all your posts, I've not seen much talk about what YOUR issues are. None of us are perfect. I know you had your own A 7 years ago. What else about Blueboy needs improvement? What are your faults and weaknesses? You need to take a good hard look at yourself and see what YOU need to change and improve. We all have room for improvement.
Me: 48 y/o W: 47 y/o Together: > 20 yrs BD: Dec '15, then S 2nd BD: Mar '16, then I filed for D April '16: started piecing