TW: self harm

Not sure if I'm allowed to post here (I don't have BPD my ex does)

Just a precursor, I think that you are all amazing and deserve the best you are good people I'm not here to hate I hope you all get the best you can.

I don't know how to help my ex, and I need advice.

We recently broke up, I understood how intense the fear of abandonment is so I did my best to reassure her and I know what and how much she's been though and I just wanted to be the one person that didn't leave and didn't hurt her so I said I would never leave unless she cheated and she reassured me that she never had and never would, I stayed when most people would of left because I saw the progress, she was starting to get better, less episode and less intense when there were any, started going to therapy eating better, sleeping more all the good stuff.

Long story short, she cheated been going on for a couple of months, when I found out I was just really hurt and depressed because that was the one thing where I draw the line she was my first and I was planning to marry her I had nearly enough money for the ring when I found out and I was honestly broken.

But now that we're no longer together she's texting me more that when we were and become a lot more attached (TW: she attempted bc I didn't text her for a few hours because I was out of service) and I'm trying my best to get her to move on and I want to help her break that attachment.

I really want the best for her and I love her to bits and care about her so much but we can't be together not after what she did I just really need advice on how best to help her or just what to do.