Whether you are dealing with 2e issues or not, it does seem that he is displaying a high level of anxiety. Sometimes continuing to examine or discuss the source of anxiety can make it continue to spiral. It may be taking all he has to keep himself "together" and talking (especially at that age) is harder to control. Have you tried tapping into his passions to get him discuss those? If those are also tied to the anxiety, try going "completely left" for awhile. Watch TED talks or the Next List, explore something on Khan Academy etc. together and talk about it. I have found that sometimes gifted students (especially if they have any type of OE issue) need permission to run with their passion or anything really academically stimulating for awhile and that will "reset" them enough to then get back to being able to discuss the issue at hand.
