I don't know but to me everyone is different. Some people have a hard time expressing their words or emotions when they are told upsetting news. it doesn't necessarily make them someone who doesn't care it just might mean they handle upsetting news in different ways. Perhaps it might be a good idea to look back and reflect onwhat it was that made you decide to be good friends with these two people. Surely there were good qualities that you all had in common that brought you to becoming friends.

Anyway try not to focus so much on what you wish they would do but rather take the time to spend more time with people who you feel can be more supportive to your needs right now. I just know that if you dwell too much on what you expect people should do you are more likely to get disappointed later on. They may surprise you and support you in their own way or they may choose not too. The important thing is that you involve more people in your life that can be supportive in ways you need. Best of luck and I hope all goes well with your health.

You have to keep close contact, for them to respond very fast, if you didn't, just call them, leave sincere message.

Some people are simply in touch with their emotions more than others. I'm sure your friends meant no disrespect; their cold, aloofness was simply their own survival mechanism kicking in. Good for self-preservation but murder on relationships.