First, I'm so sorry for all that you've been through - my heart really goes out to you
. I'm glad you found us.
I don't know if this is from being tired...I kind of doubt it. It could be hypogly, but it is weird for his age. Did he eat enough at your parents? I'm a little concerned that this could be seizure activity as well - where it begins locally then generalized (ie, when he drops). There may not necessarily be strange body movements - but were there any? Head ticking, leg moving, eye twitch, mouth ticking or anything else?