FY, I wouldn't tell her if you joined a divorce support group or signed for a divorce course...you would be setting the stage for her to seriously think about a divorce. Don't plant seeds if you want a different outcome.
Stay the course and be patient.
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.