Stay strong man, I know it's difficult but nows the time he needs you. My uncle was always my hero/idol. I literally worshipped him, most practical well thought through person I've ever met and ever will. A few years ago he was diagnosed with cancer which broke me. I couldn't visit him in hospital, couldn't think about it and tried to forget all about it as I couldn't hack it.
I grew up, fast, and visited him most evenings and free time I had. They are some of the worst memories I have of him, but I don't regret any of it. I know deep down as much as he was suffering and was quite numb to the world it meant something that people gave up their time to help him/well wish.
I know it sucks and your situations a bucket load different to mine was, but times precious, you need to stay strong and just try and stay focused on his recovery.