I'm lucky to have the man I have in my life right now. I've never met someone so understanding in my life. I can vent to him and he's always on my side.
My previous boyfriend though, was the exact opposite. It seemed like it was an inconvenience to him that I had an illness that he had to explain to his friends. When I lost a lot of weight because I lost my appetite his friends thought I was anorexic. Instead of standing up for me, he would tell me how embarrassing it was that his friends think that I'm anorexic. He would get upset with me when, after an hour or so of walking, I'd change into flip flops. He didn't get why I couldn't wear high heels, for hours, like everyone else. I never knew this until after the fact but, my mom said that she noticed him looking around, to make sure no one was looking, before he hugged me at the airport. I was embarrassing to him because I had this strange looking contraption on my hand. Sure, it wasn't the most attractive thing but it was stabilizing and strengthening my fingers. It was only a week prior, that I had undergone surgery to put my tendons put back where they belong (over my knuckles).
When I was young and newly diagnosed, my rheumatologist told me that I needed to suck it up and get on with life. Can you imagine a doctor saying this to a 12 year old? I could barely process the information at that age, let alone "get on with it". He might not have meant callous anything by it but after that, I asked to change doctors.
I am glad you were able to let him know how you feel, even though it didn't go exactly as you had hoped. Sometimes, men (and women) say things before they realize how insensitive it sounds. I think in his own way he was trying to say you can get through this and it's not a death sentence (even though at times we feel like it is). Try to keep talking to him about how you feel though as, it sounds like he's willing to, at least, try and make you feel better.