She does not want to talk about our relationship now, but it seems clear to me that she has already made up her mind. How do you stay optimistic in dark times like these? I feel like giving up hope.
Giving up? You haven't even started. This is not going to be fixed by having a relationship talk with her. I know that must be difficult to understand, especially if you are the type to work problems out by discussing it. When you have a WAW, she will not want to listen to talk about the M. She doesn't want to be around you right now.
Don't allow your fear to get the best of you. Sure, she may be thinking about D. I think all WAW's do. That doesn't mean they all go through with it.
It is usually a long process, so prepare yourself.
Btw, she was wrong to hide messages from anyone of the opposite sex. If he was just a friend, she would not feel the need for secrecy.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!