Patience. Patience, Patience. You're off to a great start...better than many of us at your stage. Here are a few thoughts:
First, you can never know what's inside your W head. You can't know her motivations and her thoughts...so don't even go there...it will drive you nuts. Focus on what YOU can do to make the sitch better and what YOU can do to make yourself better. You said that she sees you as having low self-esteem. What can you do to boost that? Food for thought. Do you have hobbies or something that you do expecially well? Can you do more of that? Can you take a class that you've always wanted to take and learn something new or do a new activity?
Secondly, I have learned from some of the successful DBers in piecing that we are resposible for filling our own tank. The love in our life and our R starts with us. We can't wait for the S to fill up our tank for us (or anything else for that matter). Treat your W and StepD with unconditional love and see how this dynamic can change things.
If you haven't already done so, go over to piecing and read some of the success stories. These folks worked HARD and, yes, this is the hardest thing you will ever do! Heck I played at Carnegie Hall 3 times and that was a piece of cake compared to this! I would suggest BillM, Sage or underdog for starters. I know that there are other good ones that I'm not thinking of at the moment (sorry no offense to other successful DBers). Some of these included OP too.
I have learned from them to ALWAYS keep a positive and self-assured demeanor around S. Focus on the positive things in your R and expand on them. Change yourself for the better. Become the person you've always wanted to be and a person that your W will find very difficult to leave. Confidence, a positive attitude and unconditional love are all MAGNETS. Become a MAGNET. You can't force your W into anything, but you can try to draw her back your way.
Also, detaching and patience. Don't take things personally and don't listen to anything she says. She will blurt out all kinds of things and, if you listen, you will become confused because that's exactly what she is.
Create poistive experiences by being positive yourself. We all know how hard this is, but you can do it. Others have and so can you!
You're off to a great start!
Read about Divorce Busting« Telephone Coaching here!