I would not necessarily put the bed wetting down to you going away. Has he been checked out by a doctor, via a urine test, to see if there is an infection there? Easily picked up at school etc. My GS started to wet the bed at about the same age and it turned out to be Type 1 diabetes. Sorry to sound the alarm on this but it needs to be checked out by a medic.
Anger management!!! Help needed.