She has rejected you over and over so why are you focussing on her feeling rejected? This is her choice, not yours. She knows that.
You were spot on when you said you were her source of comfort. If she “returns” any time soon, it will be for THAT reason only. Despite all of her contact and reaching out she has still made it perfectly clear that she doesn’t want a relationship.
The way to equip yourself for this is to stop responding to her altogether and REALLY focus on moving on. At the moment, you are focussing on her coming back to you and you are hoping NC will do that. If you keep responding to her and offering up comfort and security, she will keep on coming back for it …. and you will be stuck in this same emotional cycle. Is that what you really want?
I know it is soooo easy for us to say ignore her ….. and the truth is you probably won’t. But if she does reach out again, remind yourself WHY she is reaching out. And if you must respond, stop making yourself her source of comfort …. stop being her friend … stop making her want to reach out to you because that is what you have been doing and you’ve been doing that for one reason and one reason only.
The truth is, if you were serious about moving on from her, you would have blocked her by now.