First of all, I'm sorry for the scare. Brian's mother is a diabetic and the medics are always at her house because she passes out from low blood sugar at least once every other month. Brian is a paramedic and once while at work he got a call and it was for his mother! It's great that you how how to take care of him when he's unable to and are able to give him injections, go to appts with him to make sure you are informed, etc. etc.
Brian and I fortunately don't have any physical health issues so I can't answer that part of your question, but you seem to be "dealing" the best way you can and that's great!
PS. I hope those people who say they wouldn't be able to deal realize that when you love someone, dealing with health concerns and other struggles just comes naturally and you learn to deal the best way you can!