Hi PD - I definitely can understand your hesitation of moving forward based upon your W talking nicely. Especially since she still lies to you. It makes it hard to believe she is sincere. No one wants to be someone elses backup plan and there is nothing that prevents her from using you as a safe haven for a while.
Good for you on enjoying your life now. However, I think you know that it is nice to have someone else to share it with. It is difficult to decide whether your W will be that person.