Lava flowing? A great description. And, here I've been useing the analogy of having my limbs dipped in 'french fry oil'! His is far better! Tell him that others understand. I complement him in that he has been better to describe that PAIN better than most! He is one SMART person!
You have two issues going on at the same time tho, and both can be devastating in their own ways.
First and foremost you have to/MUST get the type one diabetes under control. For an adult it's hard...for a kid who doesn't really understand? MUCH harder. Here is a reliable JD source that mite be useful?:
http://www.jdrf.org/
IF anywhere you live there are 'classes' available? Go to them, and Take HIM, too. I wouldn't be at all surprised if he isn't adopted sort-of by many participants. IF he likes some folks, they'd be good mentors for him and ease your burdens a bit.
Second, as others have indicated...certain supplements help in the healing processes, or, at least keep some things from getting worse.
Do keep us updated on his progress? He and you are far too young to go thru this alone! Hugs '! and hope always - j