Milk snake shedding problems

[oksmartypants]

I have a 2 year-old milk that has always been perfectly healthy. He stopped shedding in March, though, and it's worrying me quite a bit. He still eats 2-3 pinkies a week, and I've always made sure my husbandry was pretty good (72-78 degrees, 50-70 humidity). I've given him a few soaks, but no shed. I think he's beginning to look a little thin on his upper body, and panicking is an understatement.

Any advice? I've tried everything I can think of/have had recommended to me.
I can post pictures if needed!