Having done basically this I can say I highly recommend not doing it. Reading your post brings up really awful feelings. Those two years were horribly stressful - I'm not sure I've fully recovered to be honest.

Furthermore, the kid has needs too, and one of those is to occasionally get your full attention, and for you to not be stressed out. I'm not sure my kids have fully recovered either.

I would use all the vacation, family leave, and sick time first, and then consider going into debt to get your wife through school.