she is noticing, that's the point, keep doing what you're doing, getting a life, not filling in the details for her, not doing things for her, being mysterious, being out of the home while she is there.
I'm certain she notices differences in you, it would be hard not to notice.
When she was planning to leave you and she went out all the time, you noticed. You noticed when she was home, what she was doing, what she was saying, when she went out, how long she stayed out, etc.
You were curious about those details.
Now you're detaching, you've created this vacuum of space between the 2 of you. You're no longer pursuing, it throws her off balance.
Now you're changing, getting a life, being different from your usual routine (which is very good, keep it up) and she is noticing.
Seriously bro, good luck on the quitting smoking, you can do it, you can do anything, never forget that - the only person that really limits you is yourself, nobody else.