What should I do?!

Hello everyone. I have never had to write about something on a public forum before, but I could use someone else's perspective on this issue.

I'm a 24 year old woman that made a friend in 2008. He is two years older than me. We used to hang out frequently and I genuinely liked our friendship as it was, but around a year later he told me he liked me. I did not want anything else so I told him how I felt and from there on our relationship got awkward and we didn't talk for a while. Eventually, we started to be friends again in 2010.

For the next four years, both of us changed a lot gradually. But I think it's only natural when you are growing up: your tastes change a little bit, you make new friends, you're studying, and in my case I got extremely focused in finishing university, thus i started to go out less and less. He, on the other hand, started dating a girl (with whom he still has a relationship to this day) and was focused in his business (he makes parties and is a dj). We didn't talk much but when we did bump into each other we would say hi and talk a little bit, although each time that happened I could feel like the bond we used to have had weakened, it was as though we barely knew each other at one point.

But then, at the beginning of 2015, a mutual friend gave me shocking news: He said that he found out my ex-friend (at 26 years old) was diagnosed with terminal cancer, and that he had some years left only if he got therapy. The news really devastated me, I couldn't believe it, so i tried to find him in facebook so I could talk to him, but that's when I realized he had erased me from his friends.

I felt the urge of talking to him and find out how he was, even when I knew we were not friends anymore. I did not have his number anymore so I sent him a friend request on facebook, which he accepted pretty quickly. I talked to him the day after, thinking that we could leave everything behind -I mean I never did anything on purpose or was mean to him. We just grew in different directions (or at least, that's MY interpretation). But the talk turned ugly pretty quickly, he said I was a bad friend and that it was all my fault that we stopped talking. That one day, he felt like I felt forced to say hi to him and his girlfriend at a party, that he had gotten really mad and when he came back home he immediately erased me from facebook. He also told me I should give him back a guitar that he had lent me when we were still friends.

I said that I was sorry if he felt that way, that it had not been my intention to have our friendship just vanish, but that i felt he had been cold towards me too. Like, I really understand my responsibility in this but in all fairness, we were both distant. I also told him that I wanted to be there for him if he needed anything, that the news of his illness had really devastated me, because of course I still care. And that I would give him back his guitar as soon as I could.

Judging by his reaction on facebook, he was pretty mad with me, full of resentment. He assured me he had got over liking me years ago and that it had nothing to do with that (I did not ask him to clarify this, he just said it). He eventually said that we could be friends again, but that i had to do all the effort, that I really had to be there for him.

He made a party to collect money for his therapy and i was there, we donated money, I talked to him in person and everything seemed better. I told him that if he needed anything, he could tell me. He seemed to appreciate the gesture.

Then in July 2015, I had a horrible car crash with my mother. She was in the hospital for days and although we are both fine now, for some weeks i couldn't even go to work (my entire body and especially my back hurt so much). So I couldn't even go to his house and see him.
But now, a couple months later, I have been wanting to go to his house to see him and give him his guitar back... but when i try to contact him he doesn't answer...(although i can see he has read the messages). It's like he went back to shutting me out of his life. He knows I got into a car accident but didn't really say much. And it was a very bad accident.

I'm a really sensitive person, I care, and everyone I talk about this tell me i care too much, that he isn't being totally reasonable. But then I think he is going through probably the worst experience ever and I can't judge him. And then I think about all the good times we used to have in the past.

This situation is really giving me anxiety. I feel guilty for neglecting our friendship in the past and that it has come to this. I know it's really tough for him and I want to be there but sometimes I feel like i'm pushing too hard. He is dying and I feel like doing something while I can, but I can't really force him either. I wish things would be smoother, it's already a terrible time for him and everyone involved.

What should I do?!