I certainly don't know how to make a plan.
1. What things has she said she wants from you or to be different? Commit to doing those things with how and timeline to accomplish.
2. Improve personal communication through reading, ic to work on fears, practice. Describe goals to better understand and empathize with BS, and to share your feelings better.
3. Buy and read 5 Love Languages with BS. Practice speaking in her language.
4. Describe how you will help with family goals, then follow through.
5. Commit to take on some of BS responsibilities so that she has time for her each week to pursue a hobby, socialize with friends, take a class, whatever.
6. Commit to figure out why you had A. Not the surface why, but the ones that explain why you had an A when you were lonely, horny, stressed, admired by AP, whatever.
7. Treatment of any addiction or addictive behaviors.
Well there is a start.