Kyrie,
Well this is an interesting situation, isn't it. I want you to know that what I write is just my opinion of how to handle this situation. There are other solutions I'm sure, but this is just my opinion as an outside source.
I would talk to Jamie. I think it's really important that you talk with him about the feelings that you're having. Even if he does get a little upset hopefully he will start to understand why you're coming to him...because you care. I'm sure it's hard to have someone that you really care about, and not feel like he's returning the feelings your way. One thing to keep into consideration, and I'm assuming this is the same boy that's going through the medical stuff, is that he has a lot of stuff on his mind right now. It's hard when you're going through stuff like that to always be thinking about others. He may not even be noticing that he's not paying you much attention, or telling you the things you need. That's why I think the best way to handle it would be to talk through all of it with him. I would hope that if he really does care about you he would be willing to talk through all of this and try to make it work.
I hope this helps you out Kyrie,
Kevin