Hi Amos,
Sounds like a very rough night, I'm so sorry!
I was on Depakote for a while, but I don't remember for sure if different foods you ate could affect your bloodlevels.... I know that is the case with Lithium, although Lithium & Depakote are not really related. Just something to consider.
Hope all is well with you and your son shortly.
Best wishes,
StarCat