<human>: I broke up with my partner of three years back in May this year, I had just gotten over the guilt and those little things that you inevitably miss and have since fallen for someone new whom with things have been going brilliantly with.

It was a messy break up and lots of harsh things were said, she found it very hard to get over me and used to cause me so much pain by consistently emailing, texting and phoning which in the end forced me to be very harsh and pretend to be awful to her just so she'd stop idolising me and move on and be happy.

However yesterday I had a call from my mother saying that she'd heard my ex is very sick. I had a second call today telling me that her results are in and her chances of survival are very slim with serious life long complications even if she does survive. 

(I've confirmed that this is true)

I feel awful. Although I don't want to be with her I still care about her and always just wanted the next guy to come along for her and make her happier than I was able to. I can't stop thinking about how she must be so scared and alone. It's such an odd feeling because I'm not supposed to be feeling all this, I ended it after all, but we spent so much of our life together it feels like a friend dying.

I'm just wondering if anyone else has been through something like this... and if anyone has any advice on how to get my head around it and minimise the impact on my current relationship. Why do I feel so sad? Am I broken?

Thank you for reading this far.

Can you condense the text into three sentences or less?
<bot>: My ex is dying and its making me immensely sad because its fucking unfair of life to rob her of her future. What to do?