My ex emailed me after 3 years of no contact

Yesterday I received an email from an ex that I haven’t heard from in 3 years. We dated in our sophomore year of college and frankly, it was a pretty toxic relationship. They were dealing with some pretty serious mental health issues (which was fine by me, as I‘ve struggled with my mental health for much of my life). I supported them through a serious mental health crisis, their bipolar diagnosis, coming out as asexual etc. but anytime I brought up an issue of my own I was brushed off or even scolded. I learned to hide any negative emotions or any issues in my life. I was always taking care of them, always worrying about them and my own issues were always on the backburner. They broke up with me because I “deserve better.” which felt like a punch to the gut. The last I heard of them, they were married to an abusive guy and their mental health was pretty erratic, but that was a while ago.

Anyways, 3 years later and I receive the following email (name and number changed, and I’d post a photo but I’m not sure how on this sub):

“I know this is crazy and selfish, I just wanted to apologize for how I treated you and how I ended our relationship. I was a shitty ass girlfriend when you deserved the world, kindness, and only love and I am deeply sorry for not providing it throughout our relationship. I won't drag you through the bs I went through, I am just working on myself and in therapy again and you deserve an apology. I still think you are the most beautiful, kind, and smart women I have ever met and I hope you have found happiness. If you ever want to reconnect or just talk feel free to reach out to me via 123-456-7891; otherwise, I won't be contacting you again, I just really wanted to apologize for treating you like shit and throwing away my shot. 

Warm regards,

Ashley <3”

I’m not really sure how to feel, but it rubbed me the wrong way that they talked about “throwing away their shot” and left their phone number? And signed with a heart? Like as much as I have empathy for what they’ve gone through and wish them well, this feels like they wrote it to make themselves feel better (and maybe for a second chance), not as a genuine apology. Whatever. I don’t have feelings for them anymore and I won’t be responding.