Hang in there Mark. The situation with my W has been up and down too. Me pursuing resulting in her pulling away. When I stopped, there was a fews days/week where she started pursuing me and inviting me to things. I got impatient that things weren't moving steadily forward, and started "us" talk again, which at one point resulted in a big fight because I wouldn't just walk away. And that has set us back to 0 again...and pushed her closer to another guy. That was a week ago and things haven't been the same since. We only talk about our son now. No more coffee breaks, invites, or hanging out. Now I wish I was back in last week and kept my patience.
But it's move on time for me. I think you must do this as well. That doesn't mean you have to give up on your marriage. It just means you have to step back from trying to fix it right now, and fix yourself first. That's the only thing you can control right now. Her anger and resentment will not let even an ounce of your pleading get to her heart. It will only backfire.
So back off a bit, do good for yourself, and be friendly with her when you do have contact. But just friendly. Friendly and happy as if you were just meeting her again for the first time. I was doing this and that is what lead my W to start inviting me to things. It didn't mean she was wanting to get back together...but she was setting aside the anger and having conversations and enjoying talking to each other which is obviously a huge positive step. The key is to not get impatient when that happens, which is very hard to do.
If she is being cordial now, just keep it up. Don't set expectations for how you think she SHOULD react to you...because they will NOT be met, and you will react to that.
Understand, that she is not going to just change her mind in a day because you smiled for a few hours. It took her a long time worth of inaction to get her to this point, it's going to take a long time of your action for her to let the anger subside and start seeing you in an emotionally neutral way. And right now she's just itching for you to make a mistake so she can prove herself right. So try not to, but don't give up if you do.