Wow Zeus, some interesting questions there from your W. I think you handled them excellently thus far.
It sounds to me like she wants answers because she is feeling uncertain about the future. She can't tell why you are making these changes. She likes them but she doesn't know if they are for real. She wants to know if you are just making the changes to get her back and then you will go back to your old ways.
And with those questioning thoughts and feelings come the next ones. Maybe you are seeing someone and that is why you are changing? Or are you changing for her? So she wants to know. I don't think she would ask if she had moved on and wasn't considering reuniting as a possibility.
Good signs I think!
How to answer? Difficult! I would say something brief and honest along the lines of: I am not currently seeing anyone, I am focused on making myself a better person right now.
And it sounds like she wants to have more heart to heart conversations so you could also say something about that like: If you have questions about what I am thinking, feeling or doing you can always ask. If you would like to meet up or talk on the phone or over email ... just let me know, I am always open to it. I would love to hear your thoughts and feelings as well. or something like that.
Good luck and let us know what you decide! Hugs, LisaB
