I would not file jointly. I would want to have my own legal representation. If she wants a divorce, then let her file. She will be the one to have the higher costs for filing and yes, leave the guilt at her door for being the one to file.

Let her do the work for the divorce since she's the one that is so gung ho on it.

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.