I think you did a good job writing what is going on inside his head.

Just had to point out that it wasn't Dean who cut off communication while Sam was at Stanford. In the Pilot, Dean said, "You could have called," and Sam didn't refute him. My understanding is that they kept at least in minimal contact for the first two or so years, but then Sam cut off contact for undisclosed reasons. (Probably because it was too hard to know what Dean and John were doing and what could be happening to them without being there and/or getting drawn back in.)

Wow. Brilliant story. Love your portrayal of Sam. Would love to see more Supernatural fic from you.