I need to vent

My wife has such depression that it makes her tired to the point as soon as she lays down she falls asleep so she put thr kids to bed and she laid down and with to sleep now her son keeps jumping up and down and keeping up my older two and scaring my 5 month old. I feel he knows when she dont feel good and uses it to get what he wants. He is being really rude and disrespectful. Hes only 2 and makes me wanna snap his neck i dobt remember my older 2 acting like this and they have special needs. Im trying not to discipline him bit i feel im going to have to since shes dead to the world