MY MARRIED LOVER HAS CANCER

Hi, I'm a gay man who has been involved with a married man (common law) for a few years.  He has several young teen aged children and lives with his girl as a family.  He claimed to be in a loveless relationship and I've always had commitment issues, so our connection seemed like a "win-win."  Eventually his feelings grew out of control and he decided that he wanted to be with me exclusively, while staying with his girl.  I fought him tooth and nail because of my commitment issues and because of the fact that he was already in a relationship.  It was very obvious to me that he was knee deep in his living situation and leaving his girl would not be an easy task.  I would have to patiently wait on the side line for the process to be complete, all while being faithful to him.  I was absolutely against it.

Long story short, last summer we had a big fight where I told him that our relationship couldn't go any further than it already had. It was a bitter discussion and some nasty things were said.  Then 3 months later he was diagnosed with NH Lymphoma.  When he called and told me, I dropped everything and came to his side.  Yes, his wife was there as well.  She knew that we were friends but had no clue about our sexual relationship.  I helped her care for him and even went with him to dr's appointments when she wasn't able to.  He experienced a LOT of complications and was near death several times.  I stood by him and helped nurse him back.  Now he's undegoing chemo treatments and is madly in love with me for being there in his time of need.

The problem is that the feelings aren't mutual. I love him, but I do not want to be in a commited relationship with him, or anyone else for that matter.  After he was stabiized enough on his chemo treatments, I started to pull back and spend less time around him and his family.  He immediately noticed and questioned me about it.   At first, I wasn't as direct as I needed to be, but eventually told him how I felt.  He's now devastated and feels like I misled him.  However, I don't feel like I did.  I love him and wanted to help him get well. I didn't and don't want to totally abandon him.  In a few days he'll be undergoing stem cell replacement therapy and will be hospitialized for a few weeks.  He told me that he and his wife have come to an agreement and that she will be moving out soon.  This bit of info has no baring on my feelings as I still don't want to be in a committed relationship with him.  

My question is what should I do?  Should I stay around to help him through the last stage of his treatment or should I just move on.  I've suggested moving on but he makes me feel selfish and guilty for even thinking about bailing out.  Now, I know that I was wrong to begin with, but I can't change the past.  And now that we're here, I really do not know what to do.  Somebody please help me...