Jen, I am thinking of you... You are such a wonderful mother and your children are blessed to have someone so caring and unselfish. You have devoted so much time to your children and Khaleb's results just go to prove that all those sleepless nights and relentless care have all been worth it.
Diabetes becomes part of our lives and often we just muddle through each crazy day and then sometimes, like on an anniversary, it triggers those intense feelings that we had when our children were diagnosed. Your feelings right now are to be expected and you know that you will 'come out the other side' so to speak.
I'm sure your eldest son understands that you have to devote more time to Khaleb, and growing up in the family will teach him to be understanding and compassionate towards other people. I'm sure he doesn't resent any of the time you spend with Khaleb and must be so proud of you.
Remember Jen, you are good at this - Khaleb's control is fantastic, many parents struggle to get control which is not nearly as good. You also do this alone and so you have achieved so much in the last 4 years.