How to help my ex-boyfriend through his sickness?

Hey guys,

I'll try to tell my story in a nutshell, but it's kind of complicated. So here we go.

My ex and I broke up three months ago after two months of being together. I couldn't deal with my life being as stressful as it was at the time. We had a fight and couldn't get past it. So after a week, he broke up with me. We agreed to be friends and try again in a month or so.

Then his best friend got in a car accident just a few days later. My dad was hospitalized for the third time in three months. Drama, drama. But alas, my ex started to ignore me. I was too dramatic/emotional apparently.

A month after we broke up, it turned out that his cancer was back and it spread this time. I was heartbroken when I heard that. He still wouldn't talk to me though.

We're two months further now. Treatments haven't helped much yet. But he is starting to reach out to me again. I'm still not fully over him. I've decided (for myself) that we're not getting back together because he obviously doesn't love me. Nonetheless, I still care about him and I want to be there for him. It's just that I'm afraid to fall for him again, spend my energy on him when he doesn't feel the same about me.

I don't know what to do, guys. Can you help me out? Give me some advice?